South Asian Journal of Research in Microbiology

Microorganisms have always been of scientific prominence and their indulgence in industrial and research facets cannot be denied. Several microorganisms have been employed as research tool to amend various parameters of industrial prominence. The current research article is from the context of significance emphasizing on the silk industry. The research article has focused on the impact of Burkholderia cepacia which is an endophytic bacterium on the silk worm and the affirmative aspects were recorded. The research work included the inoculation of the bacterium with the silk worm which has resulted in enhanced production of silk from the inoculated lot. In addition, the research has also demonstrated higher activity of protease and amylase in inoculated lot when compared to control population. The results obtained have substantiated the practical aspect of the research.

The aim of this study was to determine the antibiogram of bacterial isolates from Tympanotonus fuscatus var. radula sold in markets in Nasarawa State. Nigeria. Samples of Tympanotonus fuscatus var. radula (periwinkles) were bought from soup ingredient sellers at different sale locations in Keffi, Masaka and Orange markets and were analyzed using standard bacteriological methods. The bacterial isolates were identified using morphological, cultural and biochemical techniques. The total bacteria count varied from 1.18–3.20 x 10⁸ CFU/g for the raw samples while the total bacterial count for the boiled samples varied from 0–1.57 x 10⁸ CFU/g. Periwinkle samples with shells from Masaka market had the highest bacterial load with a mean total bacterial count of 2.94 x 10⁸ CFU/g and mean total coliform count of 2.80 x 10⁶ CFU/g. Raw periwinkle samples with shells had a higher bacterial load than samples without shells. There was also a drastic reduction in the bacterial load in the periwinkle samples after boiling under laboratory conditions. The bacteria isolated were Bacillus spp. and Staphylococcus aureus were the Gram-positive bacteria isolated. Enterobacter spp., Escherichia coli, Salmonella spp., Pseudomonas spp., Serratia spp. and Proteus spp. The most frequently occurring gram positive bacteria was Escherichia coli with an isolation frequency of 6(24%), the least frequently occurring was Bacillus spp., 8(32)%. Antibiotic susceptibility test showed that all the gram negative organisms exhibited sensitivity to ciprofloxacin: Escherichia coli (32 mm), Enterobacter spp. (41.5 mm), Proteus spp. (40.0 mm), Salmonella spp. (37.0 mm), Serratia spp. (26.0 mm), Pseudomonas spp. (23.0 mm). All the gram negative organisms showed marked resistance to vancomycin: Escherichia coli (12.0 mm), Enterobacter spp. (10.0 mm), Proteus spp. (11.0 mm), Salmonella spp. (5.0 mm), Serratia spp. (10.0 mm) and Pseudomonas spp. (4.5 mm).

Gari’ is consumed regularly by large populations of Nigeria, therefore, it is an excellent means of improving the diet of people through fortification with nutritionally rich foods hence, this study aim to produce ‘Gari’ by co-fermenting cassava mash and sprouted mung bean flour in different ratios in order to assess the effect on the nutritional composition as compared to a standard produced without sprouted mungbeans (SMF) flour fortification. In different ratios, composites of cassava mash (CM) and the sprouted mungbeans flour (SMF) were made (5% SMF + 95% CM, 10% SMF + 90% CM, 15% SMF + 85% CM; and 100% CM which serve as the control) and fermented using semi-solid state fermentation for four days. The Gari was then produced following the standard method of dewatering, sieving and roasting. Isolation of microorganism during the fermentation was carried out using standard microbiological techniques and identification was done using conventional and molecular techniques. The total bacterial (cfu/ml) of the fermented samples increased during the first day of fermentation, and reduced on subsequent days in all samples with the bacterial count ranging from 1.21 x10⁵ CFU/g to 2.45 x10⁵ CFU/g. The organisms isolated include Lysinibacillus alkalisoli, Proteus mirabilis, Pediococcus acidilactici, Lactobacillus plantarum, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Penicillium sclerotiorum, Diutina catenulate, Rhizopus stolonifer, Trichoderma viridae, Saccharomyces cerevisiae. Most of the organisms isolated during the first and second day of fermentation such as Proteus spp, Staphylococcus spp, Bacillus spp, Bacillus spp, Diutina spp and Trichoderma spp, later disappeared toward the later days of the fermentation. Lactic acid bacteria, mold and yeast isolates such as Lactobacillus plantarum, Pediococcus spp. Penicillium spp and Saccharomyces cerevisiae dominate toward the later stage of the fermentation in all the fermented samples. Molecular identification of the bacterial isolates shows that Lysinibacillus alkalisoli, Proteus mirabilis, Pediococcus acidilactici, Lactobacillus plantarum, Staphylococcus aureus, Bacillus subtilis and Bacillus cereus were present in the samples. The outcome of this research showed that co-fermentation of cassava mash and sprouted mung bean flour eliminates pathogenic microorganisms and encourages the growth of beneficial microorganism in mung bean fortified Gari production.

Fermentation and extrusion have been proven to increase the nutritional value of foods by reducing the water-binding capacity of cereal flour. Thus, the effect of fermentation and extrusion on the microbiological qualities, proximate compositions and organoleptic properties of orange flesh potato and beniseed blends were investigated using standard methods. The blended samples were prepared in four combinations (A=100 g sweet potato; B = 70 g sweet potato + 30 g beniseed; C= 60 g sweet potato + 40 g beniseed, D = 50 g sweet potato + 50 g Beniseed) and separated into four batches (i.e. first batch = preconditioned and fermented; second batch = extruded; third batch = fermented and extruded; and fourth batch = unfermented/unextruded). The blended samples were fermented for 72 hours using solid state fermentation. The bacteria isolated include Bacillus subtilis, Lactobacillus plantarum, Lactococcus lactis and Staphylococcus aureus while fungi include Mucor mucedo, Aspergillus niger, Penicillium chrysogenium, Aspergillus flavus, Geotrichum spp, Mucor mucedo and Alternaria alternate. The results of the proximate composition of the fermented and extruded blends showed a significant difference as compared with the unfermented and unextruded blends. The moisture content was highest in fermented extruded 50% sweet potato + 50% beniseed (18.61%) and least in the unfermented unextruded 50% sweet potato + 50% beniseed (4.0%). Fermentation also helps to increase the protein content and the highest was observed in composite bleed containing 50% sweet potato + 50% beniseed which increased from 2.88% to 8.75%. Extrusion also increased the protein content. The highest protein content was observed in the composite blend that was extruded and fermented (18.61). The carbohydrate content was highest in the unfermented unextruded 50% sweet potato + 50 beniseed (84.04%). The crude fat content was highest in the fermented unextruded 100% sweet potato blends (21.50%) and least in fermented extruded 50% sweet potato + 50 beniseed (2.0%). The sensory evaluation of the samples showed a good preference for the fermented-extruded samples. Findings from this research have established that orange flesh potato and beniseed blends can be fermented and extruded to produce food of enhanced nutritional value.

The impact of Egbu abattoir wastes on fungal concentrates of the soil environment was undertaken. Samples of contaminated soil from the abattoir environment were taken against control and evaluated for fungal concentrates using standard methods. Results obtained showed that total fungal count (TFC) ranged from 3.5×10⁵ cfu/g to 4.50×10⁵ cfu/g and total hydrocarbon utilizing fungi (THUF) ranged from 1.8×10⁵ cfu/g to 3.80×10⁵ cfu/g.  The percentage occurrence for mould isolates indicated the presence of Absidia sp., Aspergillus sp., Fusarium sp., Cladosporium sp., Penicillium sp., and Rhizopus sp. while yeast isolates were Candida sp., Rhodotorula sp., Saccharomyces sp., and Torulopsis sp., for both seasons. Though most of these organisms were indigenous to the soil some invading species were also isolated and were higher in contaminated soil than control soil. Egbu abattoir waste could be behind these observations. The study has revealed the impact of Egbu abattoir wastes on fungal concentrates of the soil environment.