Department of Biotechnology

Passive Biomonitoring Using Integrated Hepatic Oxidative Stress Biomarkers and Gonadal Histopathology in Oreochromis Niloticus From Lake Manyame, Zimbabwe

Fri, 01 Jan 2021 00:00:00 GMT

Passive Biomonitoring Using Integrated Hepatic Oxidative Stress Biomarkers and Gonadal Histopathology in Oreochromis Niloticus From Lake Manyame, Zimbabwe Sibonani, Sandra Mlambo; Utete, Beaven; Mudziwapasi, Reagan; Ncube, Tarshian Silibaziso; Nyamupingidza, Blessing The aquatic environment is particularly vulnerable to the effects of contaminants as effluents from municipal and industrial wastewater continually add numerous harmful exogenous compounds. Lake Manyame is a peri urban freshwater reservoi r that is subject to municipal and industrial discharge as well as agricultural run off. Adult Nile tilapia ( Oreochromis niloticus were sampled from L. Manyame during low flow and high flow seasons from selected locations. The samples were processed in th e field for histology and biochemical analysis of selected biomarkers of oxidative stress. Induction of reduced glutathione (GSH), carboxylesterase (CES) and malondialdehyde (MDA) was evident at all the sites. There were no significant variations between s it es except in the last low flow season and there was an upward trend between the first season and the subsequent sampling periods. Gonadal histology did not show occurrence of any intersex as a sign of endocrine disruption. The prevalence of histological le sions in the gonads was highest in the last sampling seasons, suggesting a progressive deterioration of water quality over time.

Geo-Nutritional Variability of Baobab (Adansonia digitata) Seeds across Diverse Agro-Ecological Zones in Zimbabwe: Insights into Macro-nutrients, Micro-nutrients and Anti nutritional Factors

Sun, 01 Feb 2026 00:00:00 GMT

Geo-Nutritional Variability of Baobab (Adansonia digitata) Seeds across Diverse Agro-Ecological Zones in Zimbabwe: Insights into Macro-nutrients, Micro-nutrients and Anti nutritional Factors Magava, Kelvin; Chigu, Nomathemba; Chisango, Tawanda; Masaiti, Tanaka The baobab tree, Adansonia digitata, is a climate-resilient indigenous species native to sub-Saharan Africa that offers significant nutritional and economic potential through its pulp and seeds. This study investigated the proximate composition of baobab seeds collected from three distinct agro-ecological zones: Mashonaland East, Masvingo, and Manicaland, to assess how geographic origin influences nutritional quality. Standard AOAC protocols were used to analyze moisture, ash, crude protein, fat, fiber, and carbohydrate content. Results revealed regional differences: Manicaland exhibited the highest mean moisture (6.22 ± 0.02%) and crude protein (20.5 ± 0.01%) levels, while Mashonaland East had the highest crude fat content (23.9 ± 0.03%). Masvingo recorded elevated carbohydrate levels (39.7 ± 0.05%) and antinutrient concentrations, including tannins (10.12 ± 1.02 g/100g), phytates (4.56 ± 0.23 g/100g), and oxalates (2.64 ± 0.02 g/100g). Statistical analysis using a one-way ANOVA test and the Tukey HSD test, revealed that a significant difference (p < 0.05) exists between seed composition from differing provinces. This reiterated the effect of genetic or environmental variation of A. digitata. It was observed that geographical location plays a significant role in impacting the nutritional composition of A. digitata, as different zones possess different compositions of macronutrients, micronutrients, and antinutrients. Such spatial effects are important in determining suitable zones suitable for the utilization of particular varieties of A. digitata. This can range from those rich with proteins for particular animal feed compositions or those rich with oil compositions. Consideration should be given to how A. digitata seed products should be valorized at national levels.

Evaluation of wheatstraw, sawdust, banana fronds,maize cobs and cotton hulls substratecombinations for Pleurotus ostreatus cultivation.

Tue, 24 Sep 2024 00:00:00 GMT

Evaluation of wheatstraw, sawdust, banana fronds,maize cobs and cotton hulls substratecombinations for Pleurotus ostreatus cultivation. Silivani, Elyson; Chisango, Tawanda Jonathan; Chitindingu, Kudakwashe; Chigu Nomathemba, Loice The yield and quality of oyster mushroom is largely dependent on the chemical and nutritional content ofthe substrate. The objective of the study was to determine the effect of different individual substratesand substrate combinations on the perfomance of P.ostreatus for growth and sustainable developmentof the mushroom cultivation industry in Zimbabwe. Various individual substrates used as treatments,selected for the cultivation of oyster mushrooms were, wheatstraw, cotton hulls, sawdust, maize cobsand banana fronds each of 1kg and replicated 4 times. Various substrate combinations, also used astreatments were, cotton hulls and wheatstraw, cotton hulls and sawdust, cotton hulls and maizecobs,cotton hulls and banana fronds in the ratio 1:1. Each combination weighed 1kg and was replicated 4times.Compound substrates perfomed much better in terms of biological effi ciency and spawn runcompared to individual substrates. The highest biological effi ciency (76%) and spawn run(17 days) wereobtained from combining cotton hulls and sawdust. Spawn run was fastest(12 days) for cotton hulls andwheatstraw combination. Analysis in terms of economic return, revealed that mushroom production wasmost profi table using cotton hulls and sawdust as substrate with a benefi t-cost ratio of 5.7 compared toother combinations of agricultural residues. In terms of spawn run, yield and economic return, combiningcotton hulls and sawdust is highly recommended for farmers involved in the cultivation of Pleurotusostreatus to satisfy increasing consumer demand, whilst decreasing pressure on limited naturalresources and preventing ecosystems degradation.

Geo-Nutritional Variability of Baobab (Adansonia digitata) Seeds across Diverse Agro-Ecological Zones in Zimbabwe: Insights into Macro-nutrients, Micro-nutrients and Anti nutritional Factors

Thu, 12 Feb 2026 00:00:00 GMT