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Bioethanol production potential of ethanol-tolerant Bacillus cereus strain GBPS9 using sugarcane bagasse and cassava peels as feedstocks was investigated. The Bacillus cereus GBPS9 used in this study was isolated from agro-wastes impacted soil and classified based on phylogenetic analysis of its 16S rRNA gene. The sequence of the isolate has been deposited in GenBank under the accession number KT318371.1. The isolate was selected based on its cellulolytic ability, tolerance to ethanol concentration of 6% (v/v) and ability to ferment sugar to ethanol. The substrates employed in the study were cassava peels and sugarcane bagasse. Chemical composition analysis showed total carbohydrate and lignin contents (% dry weight) of 69.6 ± 1.2 and 13.9 ± 0.4 for cassava peels and 70.3 ± 1.9 and 16.2 ± 1.2 for sugarcane bagasse, respectively. The feedstocks were subjected to acid, alkali and steam explosion pretreatments to increase cellulose content and therefore, reduce lignin content. The best pretreatment methods (steam explosion for sugarcane bagasse and acid for cassava peels) increased total carbohydrate contents to 85.4 ± 2.33 and 80.4 ± 2.5 for sugarcane bagasse and cassava peels, respectively. The respective lignin contents after pretreatment were 4.2 ± 0.44 and 4.8 ± 0.8 for sugarcane bagasse and cassava peels. Cultural conditions (pH, temperature, nitrogen source, inoculum size and substrate concentration) of the bacterium were optimized to enhance cellulase production. The laboratory scale fermentation of the feedstocks to ethanol was carried out in 250 mL Erlenmeyer flasks. Gas Chromatography -Mass spectrometry (GC-MS) analysis of the fermentation broth of sugarcane bagasse and cassava peels substrates revealed ethanol contents of 18.40 and 17.80 g/L, respectively. The study has demonstrated efficient bioethanol production by Bacillus cereus GBPS9 using sugarcane bagasse and cassava peels as feedstocks.

Aims: To assess the quality of abattoir effluents discharged into water bodies in Owerri Municipal, Nigeria using microbiological and physicochemical approaches. Study Design:  The study employed microbiological and physicochemical parameters to determine effluent and water quality. Place and Duration of Study: Abattoirs in Owerri, Imo State, Nigeria, between September 2014 and February 2016. Methodology: Physicochemical and microbiological analyses were carried out on three abattoir effluents and their receiving water bodies. Counts of total heterotrophic bacteria, total coliform and faecal coliform, Vibrio, Salmonella and Shigella were carried using the plate count method. Results: The bacterial isolates in the various samples included members of the genera Bacillus, Citrobacter, Enterobacter, Escherichia, Klebsiella, Lactobacillus, Listeria, Micrococcus, Proteus, Salmonella, Serratia, Staphylococcus, Streptococcus and Vibrio. The order of increasing effluent’s total coliform and faecal counts within the different abattoirs are given as Egbu abattoir > Amakohia Ikeduru abattoir > Ahiara abattoir. For the receiving streams, the order was as follows, for the total coliform count: Egbu abattoir > Ahiara abattoir > Amakohia Ikeduru abattoir while for faecal coliform: Egbu abattoir > Amakohia Ikeduru abattoir > Ahiara abattoir. About 85.7% and 42.9% of the total bacterial isolates were found in the Egbu abattoir effluent and receiving the stream, respectively. Ahiara abattoir’s effluent had 66.7% of the bacteria while its receiving stream had 23.8%. Over 57% of the total bacterial isolates were distributed in the Amakohia Ikeduru abattoir with 33.3% for its receiving stream. Conclusion: This study revealed that pathogenic bacteria from abattoir were constantly discharged into receiving streams, thereby presenting serious health risks. The health status of residents of Owerri who have access to these water bodies should be studied to determine the health implications of such unregulated practices.

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Aim: This study investigated effects of nitrogen and carbon sources on the production of biosurfactant by a hydrocarbon-utilizing bacterium, Stenotrophomonas sp. Methodology: The hydrocarbon-utilizing bacterium was isolated with Bushnell Haas (BH) broth using enrichment method. Biosurfactant production was screened by evaluating the following characteristics: Emulsification index (E-24), oil spreading (displacement), tilted glass slide, haemolysis on blood agar, and lipase production. Effects of combination of nitrogen sources (yeast extract and NH4NO3, yeast extract and urea, yeast extract and asparagine, yeast extract and peptone, NaNO3 and peptone, NaNO3 and asparagine, and yeast extract and NaNO3) and carbon sources (glucose, fructose, galactose, cassava peel, soya bran, olive oil, sucrose, crude oil, diesel and glycerol) on biosurfactant production were determined with emulsion stability and surface tension as responses. The bacterium was identified based on phenotypic, microscopic, and biochemical characteristics. Results: The isolate produced colonies on BH agar containing either naphthalene or hexadecane as sole source of carbon after 48-h incubation. Screening characteristics for the production of biosurfactant by the isolate were as follows: 46% emulsification index, 3.1 cm2 oil displacement, 1.8 cm zone of clearance on tributyrin agar, γ-haemolysis, and positive tilted glass slide. The best carbon source with the highest emulsion stability (51.6%) was fructose whereas the best surface tension reduction (30.85 mN/m) was observed with olive oil as carbon sources after 7 days of incubation. For nitrogen, the combination of yeast extract and NH4NO3 gave the highest emulsion stability (60.7%) and the best surface tension reduction (39.58 mN/m). The data obtained were significant at P<0.05 and the bacterial isolate identified as Stenotrophomonas sp. Conclusion: This study has demonstrated the ability of the hydrocarbon-utilizing bacterium, Stenotrophomonas sp. to produce biosurfactant, indicated by reduction of surface tension and formation of stable emulsion. This method of biosurfactant production can be further scaled up for industrial purpose.