Department of Biotechnology and Biological Sciences

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http://hdl.handle.net/20.500.11837/156

The Department of Biotechnology and Biological Sciences collection in DSpace at the University of Fort Hare provides access to the scholarly and research outputs of staff and students. This collection includes research articles, conference papers, and examination question papers. The Department integrates a broad range of disciplines, including Biochemistry and Microbiology, Botany, Zoology, Entomology, Biotechnology, Molecular Biology, and Genetics, to provide comprehensive teaching and research in the life sciences. Its programmes and research activities address critical challenges in health, agriculture, biodiversity conservation, food security, industry, and the environment, while promoting both fundamental and applied scientific inquiry. By preserving and disseminating these resources, the collection supports teaching, learning, and research, while contributing to scientific advancement and sustainable solutions for local and global communities.

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A comparative study of the various pretreatment techniques for bioethanol production from Kikuyu Grass
(University of Fort Hare, 2013-12) Mbande, Zukiswa Coceka
Bio-ethanol is by far the most widely used bio-fuel for transportation worldwide. Production of bio-ethanol from biomass is one way to reduce both consumption of crude oil and environmental pollution. There are mainly two processes involved in the conversion of lignocellulosic materials to ethanol production: hydrolysis of cellulose in the lignocellulosic biomass to produce reducing sugars and fermentation of the sugars to ethanol. However, pretreatment is an essential step before the hydrolysis of biomass and subsequent production of bio-ethanol. The current study was focused on four different chemical methods for the pretreatment of Kikuyu grass using mild temperatures. The temperature used was 100°C for various periods compared.
A phylogeographic assessment of South African greater cane rats (Thryonomys swinderianus): Preliminary insights
(Pensoft Publishers, 2023-03-28) Coetzer, Willem G.
The greater cane rat (Thryonomys swinderianus) is an African rodent with a wide Sub-Saharan distribution range. This species is viewed as an important protein source in many African countries. These rodents are also regularly viewed as a pest species who frequently raid croplands in agricultural settings. No phylogenetic work has to date been published on T. swinderianus from southern Africa. This paper therefore reports the first phylogenetic assessment on the species across the South African distribution range. Thirty samples were sourced from local museum collections, with one direct submission by a member of the public who found a rodent carcass identified as T. swinderianus west of its known distribution range in the Eastern Cape Province of South Africa. Two mitochondrial loci previously used in West African studies of this species were used in the current study to asses T. swinderianus population genetic diversity and phylogenetic structure across the South African distribution. A comparison to sequence data from West Africa was also performed. A divergence time estimation was conducted to further investigate the evolutionary history of the South African sub-population. Similar genetic diversity estimates were observed for the South African sub-population when compared to the West African datasets. Specimens from the eastern parts of South Africa showed higher genetic diversity estimates, possibly indicative of an initial colonisation site from eastern Africa. Two distinct phylogenetic clades were identified by Bayesian inference, forming distinct West African and South African groups. The divergence estimates showed similar ages for the T. swinderianus most recent common ancestor (MRCA) as previously reported. The MRCA estimates for the South African group identified a possible middle to late Pleistocene migratory event from eastern African into southern Africa. Further fine scale sampling across the African distribution range is however needed to provide more accurate assessments for future conservation management planning for the different sub-populations, as needed.
Advancing ethnobiology for the ecological transition and a more inclusive and just world: a comprehensive framework for the next 20 years
(BioMed Central, 2024-02-15) Albuquerque, Ulysses Paulino; Maroyi, Alfred; Ladio, Ana H.; Pieroni, Andrea; Abbasi, Arshad Mehmood; Toledo, Bárbara Arias; Dahdouh‑Guebas, Farid; Hallwass, Gustavo; Soldati, Gustavo Taboada; Odonne, Guillaume; Vandebroek, Ina; Vallès, Joan; Hurrell, Julio Alberto; de Santayana, Manuel Pardo; La Torre‑Cuadro, María de los Ángeles; Silva, María Teresa Pulido; Jacob, Michelle Cristine Medeiros; da Fonseca‑Kruel, Viviane Stern; Ferreira Júnior, Washington Soares
This opinion piece, written by ethnobiologists from different parts of the world, emphasizes the importance of ethno‑biology research in advancing contemporary biology, natural resource management, biodiversity conservation, sustainable development, and, especially, contributing to the ecological transition and a more just and inclusive world. To achieve these goals, it is essential to develop research and collaborate with social groups that live in close relationship with nature in research activities, such as Indigenous Peoples and Local Communities (IPLC), as well as Afro-descendants and other Marginalized, Minority or Minoritized Communities (AMMC). Ethnobiology can identify and provide locally appropriate solutions to local problems, enabling sustainable resource management at the landscape level. The text explores important aspects that need to be considered to guide the future of ethnobiology in the next 20 years, aiming to integrate and amplify previous discussions held in the discipline and identify points that demand ongoing attention. This paper highlights reflections from diverse researchers, emphasizing how ethnobiology can embrace different perspectives and employ rigorous analysis of complex phenomena toward effective policies and practices. This approach holds the potential to address the challenges the planet is currently facing in the coming decades.
The allelopathic potential of Arctotis Arctotoides (L.f.) O. Hoffm on some vegetables
(University of Fort Hare, 2012) Badmus, Abimbola Adesile; Afolayan, A J
Laboratory and greenhouse experiments were conducted to evaluate the allelopathic effects of the extracts and residue Arctotis arctotoides (L.f.) O. Hoffm on selected vegetable crops. The study aimed to address the following specific objectives to (i) examine the ultra structures of the leaf of A. arctotoides using the Scanning Electron Microscope (SEM), (ii) carry out comprehensive qualitative and quantitative phytochemical analysis of the root and shoot materials of the plant, (iii) investigate the allelopathic activities of the root and shoot aqueous extracts of A. arctotoides at concentrations of 10, 8, 6, 4 and 2 mg/ml on germination, radicle and plumule growth of cabbage, carrot, tomato and spinach, (iv) evaluate the inhibitory effects of the dried shoot residue of the plant at 10, 20 and 40 g kg-3 of soil (treatments B, C and D) and the control (treatment A) on the morphology, growth and chlorophyll pigment content of tomato and cabbage transplants at 1, 2, 3 and 4 weeks after transplanting and (v) assess the effects of the dried shoot residue of A. arctotoides on the yield, nutrient uptake by the leaves of tomato and cabbage at 4 and 12 weeks after transplanting. Finally, to analyze the residual mineral content of the soils with tomato and cabbage transplants at 12 weeks after transplanting. The the SEM revealed that anisocytic stomata and glandular trichomes (GTs) were numerous on the abaxial than the adaxial surfaces of A. arctotoides. The non glandular trichomes (NGTs) were also present on both surfaces but lesser on the abaxial. Morphologically, the GTs were peltate, uniseriate and globular head while the NGTs were cylindrical and filamentous with variable number of cells at the basal portion. The energy dispersive X-ray spectroscopy of some crystals showed that Na+ Mg2+ and Ca2+ were the major constituents of the crystal deposit found around the GTs and stomata. The results of the phytochemical composition of the root and shoot extracts of A. arctotoides confirmed the occurrence of alkaloids, flavonoids, phenolics, saponnins, tannins and triterpenes as the common constituents. In addition, cardiac glycosides and steroids were also detected in the shoot of the A. arctotoides. Quantitative estimation of the chemical constituents of the crude extracts further revealed that the alkaloid content in the root higher (0.97 percent) than the shoot (0.64 percent). The quantity of flavonoids detected in the shoot (1.02 percent) was more than that observed in the root (0.35 percent). Others (phenolics and tannins) were marginal in the two plant parts. The results of the inhibitory effects of the root and shoot aqueous extract at the varying concentrations showed that root extract at 10 mg/ml considerably reduced the germination of cabbage, carrot, tomato and spinach seeds by 84.0, 83.2, 72.8 and 37.4 percent respectively. Incubation of the shoot extract at the same concentration resulted in 100 percent inhibition of cabbage and carrot seed germination whereas those of tomato and spinach were suppressed by 91.5 and 61.2 percent respectively. The two extracts at the varying concentrations also had a significant reduction on the radicle and plumule growth of the four vegetables. Addition of the shoot residue to the soil showed massive chlorosis, necrotic lesions and wilting of tomato and cabbage leaves under treatments C and D at 2 weeks after transplanting. The number of leaves, leaf area, dry shoot and root weight of the two vegetables grown in the amended soils were also drastically reduced. The inhibition percentages due to the addition of the three concentrations of A. arctotoides dried shoot residue on the dry shoot weight at 4 weeks after transplanting were 38.6, 45.5 and 70.3. for tomato and 57.5, 73.3 and 87.5 percent for cabbage. Similarly, the declines in the dry root weight of 61.3, 82.9.4 and 83.4 percent for tomato as well as 53.1, 54.7 and 67.2 percent for cabbages were recorded for the two vegetables under treatment B, C and D during the period. The results further showed that the dry fruit yield and shoot weight of tomato under the treatments B, C and D decreased with increase in shoot residue concentrations of A. arctotoides. Relative to treatment A, no significant differences were recorded in the dry head weight of cabbage under the residue treated groups. The reductions in the fruit yield and fresh head weight caused by treatments C and D were 37.2 and 84.8 percent for tomato and 30.9 and 72.4 percent for cabbage. The findings on the mineral contents in the leaves of the two vegetables revealed significant differences in the uptake of N, Mg, Na, Cu and Fe by tomato leaves. The concentrations of N, K, Na and Zn in cabbage leaves also differed. However, the P content was relatively constant in the leaves of the two vegetables at 4 and 12 weeks after transplanting. At 12 weeks after transplanting, the Fe content in soils with tomato and cabbage treatments C and D was greatly enhanced in comparison with the other nutrients. The residual N, P and Zn detected in soils planted to cabbage were similarly equal among all the groups including the control. Thus, under the greenhouse experiment, Arctotis arctotoides (L.f) O. Hoffm has been shown to contain some phytotoxic chemical compounds in its root and shoot materials. The compounds either singly or collectively have demonstrated some inhibitory potentials on the germination, growth and yields of cabbage, carrot, tomato and spinach evaluated in this study.
Anatomy and Morphology of Glandular and Non-glandular trichomes of Pteronia incana in relation to their essential oil production
(University of Fort Hare, 2000-01) Mayekiso, Buyisile
The morphology and anatomy of the non-glandular. and glandular trichomes present on both abaxial and adaxial surfacea as well as on the stem surface of Pteronia incana were examined using light, scanning electron microscopy and transmission electron microscopy. The non-glandular trichomes were thread-like structures with elongated fibrous ends having a tubular basal cells. They occurred in greater abundance in both young and mature leaves and in stems. The fibrous ends of non-glandular trichomes seemed to be shielding the epidermal layer, the glandular trichome and the stoma. The electron micrograph of non-glandular trichomes showed that both trichomes originated from a single epidermal cell by anticlinal division. As the trichome matured, the cells at the end of the trichome became dehydrated and formed a thread-like fibre. Structurally, these fibrous ends were similar in composition to the components of the suberized cell walls
Animal Biology: BIO 121, Degree Examinations November 2016
(University of Fort Hare, 2016) Vumazonke, L.U.; Forbanka, D.; Tambling, C.J.
Animal Ecology 2: ZOO 325, Supplementary Examinations October/November 2025
(University of Fort Hare, 2025-11) Vine, N.; Tambling, C.J.; Marr, S.; Melville, H.
Antibacterial and phytochemical studies of selected South African honeys on clinical isolates of Helicobacter pylori
(University of Fort Hare, 2012) Manyi-Loh, Christy E; Clarke, A; Ndip, R
Infection with Helicobacter pylori has been associated with the pathogenesis of numerous stomach and gastroduodenal diseases that pose threats to public health. Eradicaftion of this pathogen is a global challenge due to its alarming rate of multidrug resistance. Consequently, to find an alternative treatment, the search is increasingly focused on new antimicrobial product from natural sources including honey. Honey has been used as medicine in several cultures since ancient time due to its enormous biomedical activities. Its beneficial qualities have been endorsed to its antimicrobial, antioxidant, anti-inflammatory properties added to its phytocomponents. In this study, the anti-H. pylori activity of South African honeys and their solvent extracts as well as the phytochemicals present in the two most active honeys were evaluated. Agar well diffusion test was used to investigate the antimicrobial activity of six honey varieties obtained from different locations in the country. Subsequently, the honeys were extracted with four organic solvents viz n-hexane, diethyl ether, chloroform and ethyl acetate employed in order of increasing polarity. The antibacterial activity of the different solvent extracts of each honey was evaluated by agar well diffusion; broth micro dilution and time kill assays. Different chromatographic techniques (Thin layer & column chromatography) were employed to enumerate the phytochemical constituents in the most active solvent extracts of Pure Honey (PH) and Champagne Royal Train (CRT); and were identified by gas-chromatography linked mass-spectrometry. Linalool pure compound was equally evaluated for anti-H. pylori activity in a bid to trace the antibacterial agent among the variety of compounds identified. Data were analyzed by One-way ANOVA test at 95% confidence interval. Crude honeys and their solvent extracts demonstrated potent anti-H. pylori activity with zone diameter that ranged from [16.0mm (crude) to 22.2mm (extract)] and percentage susceptibilities of test isolates between 73.3% (crude) and 93.3% (extract). The chloroform extracts of PH and CRT were most active with MIC50 in the ranges 0.01- viii 10%v/v and 0.625-10%v/v respectively, not significantly different from amoxicillin (P> 0.05); and efficient bactericidal activity (100% bacterial cells killed) at 1/2MIC and 4xMIC over different time intervals, 36-72hrs and 18-72hrs respectively. The appearance of bands on the thin layer chromatography (TLC) chromatogram spotted with the chloroform extracts of PH and CRT; and developed with hexane: ethyl acetate: acetic acid (HEA) and methanol: acetic acid: water (MAAW) solvent systems indicated the presence of compounds. Purification of the compounds contained in these extracts over silica gel column yielded numerous fractions which were evaluated for antibacterial activity and purity. PHF5 was the most active fraction with a mean MIC50 value of 1.25mg/mL. Volatile compounds belonging to different known chemical families in honey were identified in all the active fractions obtained from PH. Conversely, only four compounds were identified in the active fractions obtained from CRT hence the non volatile constituents could be of prime relevance with respect to antibacterial activity of this honey. Of novelty was the presence of thiophene and N-methyl-D3-azirdine compounds, essential precursors used for the synthesis of natural products and pharmaceuticals with vital biomedical properties. Linalool demonstrated potent inhibitory (MIC95, 0.002- 0.0313mg/mL) and bactericidal activity (0.0039-0.313mg/mL) against the test isolates. On the other hand, a significant difference was recorded (P < 0.05) in comparing the activity of linalool compound to the fractions. PH could serve as a good economic source of bioactive compounds which could be employed as template for the synthesis of novel anti-H. pylori drugs. However, further studies are needed to determine the non volatile active ingredients in PH and CRT as well as toxicological testing
Antibacterial evaluation of South African Aloe ferox (Mill)
(AOSIS Publishing, 2024-03-15) Goge, Sipho; Singh, Karishma; Buwa-Komoreng, Lisa Valencia; Coopoosamy, Roger M.
Background There has been an alarming increase in infections because of multidrug resistance. Several multidrug-resistant microbes are becoming more resistant to medications with several side effects. There is an urgent requirement for natural, safer and inexpensive antimicrobial agents. Aim The study sought to examine the effects of the antimicrobial activity of Aloe ferox (A. ferox) in different regions across South Africa. Method The antimicrobial activity was determined using the agar disk diffusion method. The minimum inhibitory concentration was determined using the microplate dilution method. 100 mg of dry extract was dissolved in 1 mL of ethanol, ethyl acetate and aqueous to obtain the concentration of 100 mg/mL dilutions (1:10, 1:100 and 1:500), respectively. Results The aqueous extracts showed antibacterial activity against all Gram-positive bacteria. Ethanol extracts showed greater inhibition of Gram-positive bacteria than ethyl acetate extracts. Ethanol showed inhibition on Gram-negative bacteria, that is, Protea vulgaris, Escherichia coli and S. sonnei. Aqueous and ethanol extracts displayed strong inhibition at the concentration of 1:10 against all fungal species across regions. Conclusion A. ferox showed inhibition to varying degrees across all the regions. The concentrations of A. ferox active ingredient used in traditional medicine differ by region. The study validates the potential difference in the antimicrobial activity of A. ferox across different geographical regions.
Antibacterial properties of the methanol extract of helichrysum pedunculatum
(University of Fort Hare, 2008) Ncube, Nqobile S; Okoh, Anthony I; Afolayan, A J
The methanol extract of Helichrisum pedunculatum was screened for antimicrobial activity up to a concentration of 5 mg/ml using the agar dilution technique. A number of test bacterial isolates, comprising both Gram negative and Gram positive organisms were susceptible to the crude extract of the plant. The minimum inhibitory concentrations (MICs) of the extract ranged between 1 and 5 mg/ml for the susceptible organisms. The MICs of the selected antibiotics, chloramphenicol and penicillin, ranged between 2 and 4 mg/L, and 2 and 32 mg/L respectively against Bacillus cereus, Proteus vulgaris and Staphylococcus aureus OKOH1. Bactericidal activity was determined by the time kill assay. The methanol extract of the plant was not bactericidal at 1 × MIC for B. cereus, P. vulgaris and Staph. aureus OKOH1. At 2 × MIC the extract was bacteriostatic against B. cereus but bactericidal against P. vulgaris and Staph. aureus OKOH1. Combination studies were done at 1/2 × MIC, 1 × MIC and 2 × MIC of the plant extract with 1 × MIC of the antibiotics. Combinations of the plant extract and chloramphenicol resulted in mostly indifferent interactions against P. vulgaris and Staph. aureus OKOH1 but synergistic interactions at higher concentration of the plant extract for B. cereus. Penicillin combinations gave synergistic interactions at lower concentrations of the plant for P.vulgaris and Staph. aureus OKOH1 but was mostly indifferent for B. cereus.
Antibiogram profiling of Escherichia coli pathotypes isolated from Kat River and Fort Beaufort abstraction water
(University of Fort Hare, 2014) Nontongana, Nolonwabo; Okoh, Anthony I
Escherichia coli (E. coli) is a widespread species that includes a broad variety of strains, ranging from highly pathogenic strains causing worldwide outbreaks of severe disease to virulent isolates which are part of the normal intestinal flora or which are well characterized and safe laboratory strains. The pathogenicity of a given E. coli strain is mainly determined by specific virulence factors which include adhesins, invasins, toxins and capsule. The aim of this study was to evaluate the prevalence and antibiogram profiles of E. coli pathotypes previously isolated from Kat River and Fort Beaufort abstraction water. A total of 171 E. coli isolates showed at least one pathogenic determinant among the isolated 278 E. coli. The other 107 isolates were negative for the tested virulence genes. All 278 presumptive isolates tested positive for the UidA gene, and were therefore classified as non-categorized pathogenic E. coli. The 171 pathogenic isolates had at least one characteristic gene of pathogenic E. coli and were identified and classified as enteropathogenic E. coli (6%), enterotoxigenicE. coli (131), uropathogenic E. coli (6), neonatal meningitis E. coli (14), diffusely adherent E. coli (1) and enterohaemrrhagic E. coli (1). Interestingly, no virulence genes were detected for the enteroinvasive E. coli and the enteroaggregative E. coli. The antibiotic resistance profiles for all isolates that were identified as E. coli showed 100% resistance to penicillin G, 98% resistance to ampicillin, 38% resistance to trimethoprim-sulphamethoxazole and 8% resistance to streptomycin. Multiple antibacterial resistance (MAR) was also observed, where 44% of the isolates were resistant to three antibiotics and 8% resistant to four antibiotics. The results of this study showed the Kat River and Fort Beaufort abstraction water are reservoirs of pathogenic strains of E. coli which harbour antibiotic resistance determinants that can cause serious health risks to the people in the surrounding communities.
Antibiogram profiling of Escherichia Coli pathotypes isolated from Kat River and Fort Beaufort abstraction water.
(University of Fort Hare, 2014) Nontongana, Nolonwabo
Escherichia coli (E. coli) is a widespread species that includes a broad variety of strains, ranging from highly pathogenic strains causing worldwide outbreaks of severe disease to virulent isolates which are part of the normal intestinal flora or which are well characterized and safe laboratory strains. The pathogenicity of a given E. coli strain is mainly determined by specific virulence factors which include adhesins, invasins, toxins and capsule. The aim of this study was to evaluate the prevalence and antibiogram profiles of E. coli pathotypes previously isolated from Kat River and Fort Beaufort abstraction water. A total of 171 E. coli isolates showed at least one pathogenic determinant among the isolated 278 E. coli. The other 107 isolates were negative for the tested virulence genes. All 278 presumptive isolates tested positive for the UidA gene, and were therefore classified as non-categorized pathogenic E. coli. The 171 pathogenic isolates had at least one characteristic gene of pathogenic E. coli and were identified and classified as enteropathogenic E. coli (6%), enterotoxigenicE. coli (131), uropathogenic E. coli (6), neonatal meningitis E. coli (14), diffusely adherent E. coli (1) and enterohaemrrhagic E. coli (1). Interestingly, no virulence genes were detected for the enteroinvasive E. coli and the enteroaggregative E. coli .The antibiotic resistance profiles for all isolates that were identified as E. coli showed 100% resistance to penicillin G, 98% resistance to ampicillin, 38% resistance to trimethoprim-sulphamethoxazole and 8% resistance to streptomycin. Multiple antibacterial resistance (MAR) was also observed, where 44% of the isolates were resistant to three antibiotics and 8% resistant to four antibiotics. The results of this study showed the Kat River and Fort Beaufort abstraction water are reservoirs of pathogenic strains of E. coli which harbour antibiotic resistance determinants that can cause serious health risks to the people in the surrounding communities.
Antibiotic resistance and virulence genes profiling of Vibrio cholerae and Vibrio mimicus isolates from some seafood collected at the aquatic environment and wet markets in Eastern Cape Province, South Africa
(Public Library of Science, 2023-08-24) Abioye, Oluwatayo E.; Nontongana, Nolonwabo; Osunla, Charles A.; Okoh, Anthony Ifeanyi; Venkitanarayanan, K.
The current study determines the density of Vibrio spp. and isolates V. cholerae and Vibrio mimicus from fish-anatomical-sites, prawn, crab and mussel samples recovered from fish markets, freshwater and brackish water. Virulence and antibiotic resistance profiling of isolates were carried out using standard molecular and microbiology techniques. Vibrio spp. was detected in more than 90% of samples [134/144] and its density was significantly more in fish than in other samples. Vibrio. cholerae and V. mimicus were isolated in at least one sample of each sample type with higher isolation frequency in fish samples. All the V. cholerae isolates belong to non-O1/non-O139 serogroup. One or more V. cholerae isolates exhibited intermediate or resistance against each of the eighteen panels of antibiotics used but 100% of the V. mimicus were susceptible to amikacin, gentamycin and chloramphenicol. Vibrio cholerae exhibited relatively high resistance against polymyxin, ampicillin and amoxicillin/clavulanate while V. mimicus isolates exhibited relatively high resistance against nitrofurantoin, ampicillin and polymixin. The multiple-antibiotic-resistance-index [MARI] for isolates ranges between 0 and 0.67 and 48% of the isolates have MARI that is >0.2 while 55% of the isolates exhibit MultiDrug Resistance Phenotypes. The percentage detection of acc, ant, drf18, sul1, mcr-1, blasvh, blaoxa, blatem, blaoxa48, gyrA, gyrB and parC resistance-associated genes were 2%, 9%, 14%, 7%, 2%, 25%, 7%, 2%, 2%, 32%, 25% and 27% respectively while that for virulence-associated genes in increasing other was ace [2%], tcp [11%], vpi [16%], ompU [34%], toxR [43%], rtxC [70%], rtxA [73%] and hyla [77%]. The study confirmed the potential of environmental non-O1/non-O139 V. cholerae and V. mimicus to cause cholera-like infection and other vibriosis which could be difficult to manage with commonly recommended antibiotics. Thus, regular monitoring of the environment to create necessary awareness for this kind of pathogens is important in the interest of public health.
Antifugal evaluation and phytochemical analysis of selected medicinal plants used in the treatment of fungal diseases associated with HIV infection in the Eastern Cape Province, South Africa
(University of Fort Hare, 2013) Mbeng, Wilfred Otang; Grierson, Donald S; Ndip, Roland, N
Background. As a result of the AIDS pandemic, many people areimmuno compromised andopportunistic fungal infections (OFIs) such as candidiasis are common. Despite the widespread use of medicinal plants in South Africa, there is a dearth of knowledge regarding the use of such plants in the management of these infections. This study evaluates three South African medicinal plants (Arctotis arctotoides, Pittosporum viridiflorum, and Gasteria bicolor) traditionally used in the treatment of OFIs in HIV/AIDS patients, in the Eastern Cape Province, South Africa. Materials and methods. A six-stage process of documentation, evaluation and analysis of results was conducted: (1) Selection of medicinal plants most frequently used in the treatment of OFIs through ethnomedical studies and the survey of specialised literature; (2) Collection and preparation of the extract of each plant; (3) Antifungal evaluation of the crude plant extracts. (4) Phytochemical and antioxidant evaluation of the active crude plant extracts; (5) Cytotoxicity evaluation of the bioactive extracts using the Chang liver cell line, and (6) Statistical analysis of the results. Ethnobotanical information was obtained through interviews with traditional healers and AIDS patients with the aid of semi-structured questionnaires, direct observations and by reviewing studies reported in the literature. Following the approval from the University of Fort Hare‘s Ethics Committee, 101 HIV/AIDS patients were recruited through convenience sampling into an anonymous cross-sectional questionnaire study. The agar diffusion and micro-dilution methods were used to determine the antifungal activities of the hexane, acetone and aqueous extracts of A. arctotoides, G. bicolor and P. viridiflorum against 10 opportunistic fungi.
Assessment of antibacterial potentials of Garcinia Kola seed extracts and their interactions with antibiotics
(University of Fort Hare, 2007) Sibanda, Thulani; Okoh, Anthony I
The antibacterial potency of the extracts of the seed of Garcinia kola (bitter kola) was investigated in this study against a panel of referenced, environmental and clinical bacterial strains. The killing rates of the active extract as well as their potential for combination antibacterial therapy with standard antibiotics were also elucidated using standard procedures. The aqueous and acetone extracts of the seed were screened for activity against 27 bacterial isolates. The aqueous extract exhibited activity mainly against Gram positive organisms with Minimum inhibitory concentration (MIC) values ranging from 5 mgml-1 – 20 mgml-1, while the acetone extract showed activity against both Gram negative and Gram positive organisms with MIC values ranging from 10 mgml-1 - 0.156 mgml-1. The acetone extract also showed rapid bactericidal activity against Staphylococcus aureus ATCC 6538 with a 3.097 Log10 reduction in counts within 4 hours at 0.3125 mgml-1 and a 1.582 Log10 reduction against Proteus vulgaris CSIR 0030 at 5 mgml-1 after 1 hour. In addition, the aqueous, methanol and acetone extracts of the seeds also exhibited activity against four clinical strains of Staphylococcus isolated from wound sepsis specimens. The MIC values for the aqueous extract were 10 mgml-1 for all the isolates while the acetone and methanol extracts had lower values ranging from 0.3125 - 0.625 mgml-1. The acetone extract was strongly bactericidal against Staphylococcus aureus OKOH3 resulting in a 2.70 Log10 reduction in counts at 1.25 mgml-1 within 4 hours of exposure and a complete elimination of the organism after 8 hours. The bactericidal vi activity of the same extract against Staphylococcus aureus OKOH1 was weak, achieving only a 2.92 Log10 reduction in counts at 1.25 mgml-1 (4× MIC) in 24 hours. In the test for interactions between the acetone extract of the seeds and antibiotics, synergistic interactions were observed largely against Gram positive organisms using the FIC indices, (indices of 0.52 - 0.875) with combinations against Gram negatives yielding largely antagonistic interactions (indices of 2.0 to 5.0). Synergy (≥ 1000 times or ≥ 3 Log10 potentiation of the bactericidal activity) against both Gram negative and Gram positive organisms was detected by time kill assays mainly involving the antibiotics tetracycline, chloramphenicol, amoxycillin and penicillin G. Combinations involving erythromycin and ciprofloxacin consistently gave antagonistic or indifferent interactions. We conclude that the acetone extract of Garcinia kola seeds possess strong bactericidal activities against both Gram positive and Gram negative organisms and can be therapeutically useful in the treatment of bacterial infections including the problematic staphylococcal wound infections. In addition, the acetone extract can be a potential source of broad spectrum resistance modifying compounds that can potentially improve the performance of antibiotics in the treatment of drug resistant infections.
Assessment of antibiotic production by some marine Streptomyces isolated from the Nahoon Beach
(University of Fort Hare, 2010) Ogunmwonyi, Isoken Nekpen Henrietta
Rapidly emerging strains of bacteria resistant to most advanced antibiotics have become issues of very important public health concern. Research currently directed towards marine actinomycetes presents a vast potential for new compounds that could be able to safely and effectively target resistant species. In this regard, ten putative Streptomyces strains isolated from the Nahoon beach were selected and assessed for antibiotic production and activity against a wide range of bacteria including reference strains, environmental strain and clinical isolates. The ethyl acetate extracts of the putative Streptomyces isolates showed activities against at least 6 and up to 26 of the 32 test bacteria. Inhibition zones were found to range between 9-32 mm diameters at a concentration of 10 mg/ml. The minimum inhibitory concentrations (MICs) of the crude extracts ranged from 0.039 - 10 mg/ml and the least minimum bactericidal concentration (MBC) demonstrated was 0.625 mg/ml against a reference strain Staphylococcus aureus ATCC 6538. Time kill kinetics of all extracts revealed bacteristatic and bactericidal activities. Average Log reductions in viable cell counts for all the extracts ranged from 0.86 Log10 and 3.99 Log10 cfu/ml after 3 h interaction and 0.01 Log10 and 4.86 Log10 after 6 h interaction at MIC, 2 × MIC, 3 × MIC and 4 × MIC concentrations. Most of the extracts were speedily bactericidal at 3 × MIC and 4 × MIC resulting in over 50 % elimination of most of the test bacteria within 3 h and 6 h interaction. The partial characterization of the crude extracts by IR spectral analysis revealed possibility of terpenoid, long chain fatty acids and secondary amine derivatives compounds in the extracts. It is therefore recommended that further investigation should address the relationship between the structure of the active component of the extracts and the broad spectrum activity, as well as a rapid method for large scale production and purification and whether this group of antibiotics has any application in managing human infectious disease..
Assessment of antibiotic production by some marine Streptomyces isolated from the Nahoon Beach
(University of Fort Hare, 2010) Ogunmwonyi, Isoken Nekpen Henrietta; Okoh, I
Rapidly emerging strains of bacteria resistant to most advanced antibiotics have become issues of very important public health concern. Research currently directed towards marine actinomycetes presents a vast potential for new compounds that could be able to safely and effectively target resistant species. In this regard, ten putative Streptomyces strains isolated from the Nahoon beach were selected and assessed for antibiotic production and activity against a wide range of bacteria including reference strains, environmental strain and clinical isolates. The ethyl acetate extracts of the putative Streptomyces isolates showed activities against at least 6 and up to 26 of the 32 test bacteria. Inhibition zones were found to range between 9-32 mm diameters at a concentration of 10 mg/ml. The minimum inhibitory concentrations (MICs) of the crude extracts ranged from 0.039 - 10 mg/ml and the least minimum bactericidal concentration (MBC) demonstrated was 0.625 mg/ml against a reference strain Staphylococcus aureus ATCC 6538. Time kill kinetics of all extracts revealed bacteristatic and bactericidal activities. Average Log reductions in viable cell counts for all the extracts ranged from 0.86 Log10 and 3.99 Log10 cfu/ml after 3 h interaction and 0.01 Log10 and 4.86 Log10 after 6 h interaction at MIC, 2 × MIC, 3 × MIC and 4 × MIC concentrations. Most of the extracts were speedily bactericidal at 3 × MIC and 4 × MIC resulting in over 50 % elimination of most of the test bacteria within 3 h and 6 h interaction. The partial characterization of the crude extracts by IR spectral analysis revealed possibility of terpenoid, long chain fatty acids and secondary amine derivatives compounds in the extracts. It is therefore recommended that further investigation should address the relationship between the structure of the active component of the extracts and the broad spectrum activity, as well as a rapid method for large scale production and purification and whether this group of antibiotics has any application in managing human infectious disease.
Assessment of bioflocculant production by some marine bacteria isolated from the bottom sediment of Algoa Bay
(University of Fort Hare, 2010) Cosa, Sekelwa; Okoh, Anthony I
Several problems concerning the use of conventional synthetic flocculants has necessitated the need for alternative cost effective, safe and efficient bioflocculants from microorganisms inhabiting many environments, particularly those from unusual environments. Hence, this study assessed bioflocculant production by three marine bacteria isolated from the bottom sediment of Algoa Bay in the Eastern Cape Province of South Africa. Analysis of the 16S rDNA sequences led to their identification as Halobacillus sp. Mvuyo, Virgibacillus sp. Rob and Oceanobacillus sp. Pinky. Several factors affecting the production and activity of the bioflocculant(s) were studied. Halobacillus sp. Mvuyo produced bioflocculant optimally with glucose (76%) and ammonium chloride (93%) as sole carbon and nitrogen sources, respectively and at neutral pH and in the presence of Ca2+. On the other hand, Virgibacillus sp. Rob preferred glucose (70.4 %) and iron sulphate (74%) as carbon and nitrogen source respectively; an alkaline pH (12.0) and Fe2+. Oceanobacillus sp. Pinky produced bioflocculant optimally when sucrose (80%) and peptone (72.4 %) were used as carbon and nitrogen source respectively, at neutral pH, and in the presence of Ca2+ cation. The chemical analyses of the partially purified bioflocculants revealed that the bioflocculants produced by Halobacillus sp. Mvuyo and Oceanobacillus sp. Pinky were glycoproteins, while that produced by Virgibacillus sp. Rob was a polysaccharide. We thus conclude that Halobacillus sp. Mvuyo, Virgibacillus sp. Rob and Oceanobacillus sp. Pinky hold promise as producers of new and efficient bioflocculant(s). We recommended development of process conditions for large scale production of the bioflocculants followed by their detailed characterization, as well as pilot scale assessment of the applicability of the purified bioflocculant in water/wastewater treatment and other industrial uses
Assessment of bioflocculant production by two marine bacteria isolated from the bottom sediment of marine Algoa Bay
(University of Fort Hare, 2015) Ntozonke, Ncedo; Prof. Okoh, A I
Bioflocculants are polymers, mostly, of microbial origin which floc out suspended particles from liquid medium. The ability of these biopolymers to remove suspended particles from solutions is termed bioflocculation, and the efficiency of flocculation activities depends on the characteristics of the flocculants. In comparison with conventionally used flocculants, bioflocculants have the advantage of being safe (no toxic effects known), biodegradable and harmlessness to the environment. The study assessed production of bioflocculant by two marine bacteria from the bottom sediment of marine environment. The 16S rDNA was used for identification, and the two bacteria species were identified as Enterococcus hirae and Bacillus thuringiensis. Factors affecting the production and activity of the bioflocculants produced by these two organisms were studied. The bacteria optimally produced bioflocculant with fructose (91.7%) and urea (91%) as sole carbon and nitrogen sources respectively. Mg2+ (87%) and Ca2+ (86%), likewise, served as best cation sources on the production of the bioflocculant at pH 5(93%). Additionally, the flocculating activity of the bioflocculant increased with the addition of Mg2+ (81%) and Na+ (81%), and the highest flocculating activity was at pH 5 of the kaolin clay. The Fourier transform infrared spectroscopy (FTIR) shows that the bioflocculant is a glycoprotein. The second bacterium (Bacillus thuringiensis) produced bioflocculant optimally when the media had mixed nitrogen sources (Urea, ammonium chloride and tryptone (67%)) and glucose (85.65%) as a sole carbon source, also Ca2+ (74.6%) was the best cation that induced the production of bioflocculant. After purification, the bioflocculant flocculated optimally in alkaline pH 12 (81%) in the presence of Mn2+ (73%) and Ca2+ (72.8%). Chemical analysis of the bioflocculant revealed it to be a polysaccharide. Both bioflocculants flocculate efficiently and can be used to replace synthetic flocculants in water treatment, wastewater, in downstream processing, and processing of food and chemicals and other industrial uses of flocculants. Challenges though (i) are to develop conditions for large scale production of the bioflocculant, (ii) to do further characterization of the both bioflocculants (iii) to assess the bioflocculants for treatments of water/wastewater, and to apply it in various industrial processes.
Assessment of bioflocculant production by two marine bacteria isolated from the bottom sediment of marine Algoa Bay
(University of Fort Hare, 2015) Ntozonke, Ncedo; Okoh, Anthony I; Nwodo, Uchechukwu U
Bioflocculants are polymers, mostly, of microbial origin which floc out suspended particles from liquid medium. The ability of these biopolymers to remove suspended particles from solutions is termed bioflocculation, and the efficiency of flocculation activities depends on the characteristics of the flocculants. In comparison with conventionally used flocculants, bioflocculants have the advantage of being safe (no toxic effects known), biodegradable and harmlessness to the environment. The study assessed production of bioflocculant by two marine bacteria from the bottom sediment of marine environment. The 16S rDNA was used for identification, and the two bacteria species were identified as Enterococcus hirae and Bacillus thuringiensis. Factors affecting the production and activity of the bioflocculants produced by these two organisms were studied. The bacteria optimally produced bioflocculant with fructose (91.7%) and urea (91%) as sole carbon and nitrogen sources respectively. Mg2+ (87%) and Ca2+ (86%), likewise, served as best cation sources on the production of the bioflocculant at pH 5(93%). Additionally, the flocculating activity of the bioflocculant increased with the addition of Mg2+ (81%) and Na+ (81%), and the highest flocculating activity was at pH 5 of the kaolin clay. The Fourier transform infrared spectroscopy (FTIR) shows that the bioflocculant is a glycoprotein. The second bacterium (Bacillus thuringiensis) produced bioflocculant optimally when the media had mixed nitrogen sources (Urea, ammonium chloride and tryptone (67%)) and glucose (85.65%) as a sole carbon source, also Ca2+ (74.6%) was the best cation that induced the production of bioflocculant. After purification, the bioflocculant flocculated optimally in alkaline pH 12 (81%) in the presence of Mn2+ (73%) and Ca2+ (72.8%). Chemical analysis of the bioflocculant revealed it to be a polysaccharide. Both bioflocculants flocculate efficiently and can be used to replace synthetic flocculants in water treatment, wastewater, in downstream processing, and processing of food and chemicals and other industrial uses of flocculants. Challenges though (i) are to develop conditions for large scale production of the bioflocculant, (ii) to do further characterization of the both bioflocculants (iii) to assess the bioflocculants for treatments of water/wastewater, and to apply it in various industrial processes.

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