DSpace Community: SLS

Assessement of Fish Diversity in Relation to Fishing Gear Efficiency in Tagwai Lake Minna, Nigeria

Mon, 23 Oct 2017 00:00:00 GMT

Title: Assessement of Fish Diversity in Relation to Fishing Gear Efficiency in Tagwai Lake Minna, Nigeria Authors: Chukwumeka, V.I.; Arimoro, F.O.; Auta, Y.I.; Olisadebe, O.J.; Erhabor, O.F. Abstract: The fish fauna of Tagwai Lake, Niger State, Nigeria was studied between February and August, 2016. The catch assessment was conducted at the landing site bi-weekly. Simple descriptive statistical tools such as simple percentage, frequency counts were used to analyze data obtained. A total of 53,442 fishes belonging to 7 families and 8 species were identified namely: Tilapia zill, Sarotherodon galilaeus, Alestes dentex, Auchenoglanis occidentalis, Clarias gariepinus, Mormyrus hasselquistii, Chrysicthys auratus, and Odaxothrissa mento. In terms of number, the Family: Clupeidae dominated the catch, and contributed 46.98% to the total catch. This was followed by the Cichlidae (43%), Alestidae (7.03%), Bagridae (2.08%), Clarotidae (7%), Claridae (0.42%), Mormyridae (0.00%). In terms of weight, the Cichlidae family was dominant (40.84%) for the total weight of fish caught. Cichlidae was also the most diversified family, represented by 2 species. The results showed the species abundance to be: Tilapia zillii (21.96), Sarotherodon galilaeus (21.04%), Odaxothrissa mento (46.98%), Alestes dentex (7.033%) and Auchenoglanis occidentalis (2.08%) in Tagwai Lake. Cast nets and gill nets were the most productive fishing gear with a total catch of 33, 555 and 7095 fishes respectively. Hook-and-line yielded no catch. The predominantly used gear between the month of July and August were Trap nets (Wire trap and the Gura Malian trap) The dominant species in cast net collections was T. galilaeus (32.60%) while that of Gill net was O. mento (59.48%). As a management strategy for this Lake, fishing activities should be monitored periodically to avoid the use of inappropriate gear for fishing.

Isolation and screening of xylanase-producing microorganisms.

Mon, 01 Jan 2024 00:00:00 GMT

Title: Isolation and screening of xylanase-producing microorganisms. Authors: Oyewole, O.A.,; Binuyo, O.A.,; Joda, J.F.,; Nabara, H.Y.,; Tsado, P.Y.,; Musa, F.,; Akinpelu, O.J. Abstract: Xylanases are enzymes that break down the complex polysaccharide xylan, the major component of hemicellulose. Xylanase hydrolyzes xylan by breaking the β-1,4- glycoside linkage to produce xylose and other degradation compounds. Many degradative microorganisms such as fungi, bacteria and yeast have been found to produce xylanases. In this study, xylanase-producing microorganisms were isolated from different environmental samples - paddy field rhizosphere, earthen pond sludge, decayed wood, cow dung, and sediments from Tagwai Dam, Minna, Nigeria. The samples were serially diluted and plated on a selective agar medium, which contains xylan (1.5 g), peptone (5 g), yeast extract (3 g), sodium chloride (5 g), and agar (15 g) per 1 L of distilled water using spread plate method and incubated at 37 °C for 48 hours and 25 °C for 5 days for bacteria and fungi respectively. The plate screening method was used to screen the microbial isolates for xylanase activity. Colonies with zones of inhibition indicated xylanase activity. Positive isolates were further subcultured to obtain pure isolates and were kept in slant bottles and stored at 4°C for further analysis. The pure isolates were cultured in nutrient broth for bacteria and Sabouraud dextrose broth for fungi and from the broth, into selective broth which was used to determine xylanase activity using DNS (dinitrosalicylic acid) method. The bacterial isolates were identified based on their cultural, morphological and biochemical characteristics while the fungal isolates were stained with lactophenol cotton blue. Ten (10) bacteria were isolated from the samples, of which four (Clostridium sp., Escherichia coli, Salmonella sp., and Staphylococcus sp) were xylanase producers and four (4) xylanase-producing fungi (Aspergillus niger, A. fumigatus, A. flavus, and A. sydowii were identified for fungi) were isolated. Escherichia coli gave the highest activity for the bacteria (0.8260) while Aspergillus flavus gave the highest xylanase activity for fungi (2.1118). Aspergillus flavus can therefore be recommended for large-scale production of xylanase.

Microbial production of lysine from agrowastes.

Thu, 01 Jan 2026 00:00:00 GMT

Title: Microbial production of lysine from agrowastes. Authors: Gana, M.,; Abioye, O.P.,; Oyewole, O.A.,; Akande, K.O.,; Haruna, A. Abstract: Lysine is a crucial amino acid that the body cannot produce but critical for overall health. Conventional lysine production is expensive, hazardous to the environment, and depends on refined substrates; therefore, a sustainable alternative that uses agricultural waste is required. The aim of this study was to produce lysine by bacteria using agro wastes as substrate. The objectives include isolating and screening lysine producing bacteria from soil sample, characterizing and identifying the lysine producing bacteria, screening agro-wastes (groundnut shell, corn cob, and sugarcane bagasse), optimizing the conditions for production and extracting and purifying lysine. Bacillus subtilis was isolated and utilized for fermentation while Gas Chromatography-Mass Spectrometry (GC-MS) was employed for lysine quantification. The result showed that the three agro wastes were found to support lysine production, serving as carbon sources. However, corn cob poses to be the best carbon source for the bacterium. B. subtilis with lysine concentration of 1.41g/L under pH of 7, temperature of 32.50 °C, and a carbon concentration of 12.50% . The genetic modification of Bacillus subtilis to enhance its metabolic pathways for lysine synthesis should be the primary focus of further research and development.

Microplastics distribution in the soil: A review

Fri, 02 Jan 2026 00:00:00 GMT

Title: Microplastics distribution in the soil: A review Authors: Auta, Helen Shnada; Musa, Innocent Ojeba; Aransiola, Sesan Abiodun; Makun, H. A; Hassan, Auwalu; Ijah, Udeme Josiah Joshua; Aboyeji, David Oyeyemi; Fauziah, Shahul Hamid; Maddela, Naga Raju; Prasad, Ram Abstract: The pervasive use of plastics in modern society has led to significant environmental concerns about plastic pollution. As demand for plastic materials continues to rise, the improper disposal of plastic waste poses a substantial threat to both marine and terrestrial ecosystems. Microplastics, defined as plastic debris <5 mm in diameter, have emerged as a contaminant of global significance. While extensive research has focused on microplastic pollution in oceans, the impact on terrestrial environments remains understudied. The heterogeneous distribution of microplastics raises concerns about soil health, nutrient cycling, and crop productivity. Microplastics are not uniformly distributed across soil profiles. Instead, they often accumulate in topsoil layers where they interact with plant roots, microorganisms, and soil fauna. Their presence has been linked to changes in soil structure, reduced water holding capacity, and disruptions in microbial community dynamics. Understanding the patterns, pathways, and mechanisms governing microplastic distribution is therefore critical for developing informed mitigation strategies. If the food chain is disrupted, it can have negative impacts on soil biota, raising worries about human health. In this review, microplastics’ impacts on soil biogeochemistry and their interactions with soil organisms are discussed, along with their properties, research trends, and other factors. Recent findings suggest that soil serves as a primary sink and transporter of microplastics, which can then enter aquatic ecosystems and affect soil biota, potentially disrupting the food chain and human health. We emphasize the need for ongoing study into the impact of microplastics on terrestrial ecosystems.