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.

1. The roles of chronological age, body weight and body composition in the initiation of sexual maturation of Japanese quail (Coturnix coturnix japonica) were investigated by imposing an inhibitory photoperiod (IP), and by the intramuscular injection of turkey growth hormone (GH) or antisera to turkey growth hormone (AGH). 2. Absence of sexual maturity in the IP treatment was accompanied by reduced testis and ovary-oviduct weights, and an increased breast muscle weight expressed as a proportion of body weight. 3. Antisera to turkey growth hormone (AGH) did not completely inhibit the metabolic activities of endogenous GH. 4. The roles of chronological age, body weight and body composition in the initiation of sexual maturity were inseparable.

1. Hyperplastic growth of adipose tissue in Japanese quail (Coturnix coturnix japonica) was examined in relation to sexual maturity to determine whether fat cell number is fixed in mature individuals of this species.2. Total DNA concentrations in the lipid (lipocyte) and non-lipid (stroma) fractions of collagenase (EC 3.4.24.3)-digested abdominal (retroperitoneal) fat depots were determined on a chronological-age basis from 28 to 240 d of age. The in vivo incorporation of [methyl-3H]thymidine into DNA of both the lipocyte and stroma fractions of abdominal fat from both ad lib. and restricted-fed (75% of ad lib.) females was also examined at ages before and subsequent to sexual maturity.3. In both males and females, significant increases in abdominal fat weights at ages beyond sexual maturity were associated with increased lipocyte DNA. Regardless of the feeding regimen and stage of maturity, substantial radioactivity was recovered from both the stromal and lipocyte fractions of abdominal fat when female quail were examined 24 h after the administration of tritiated thymidine. When examined 5 d post-injection, the majority of the radioactivity was contained in the lipid fraction of collagenase-digested adipose tissue.4. Both the total DNA content of adipose tissue and the incorporation of tritiated thymidine into adipose tissue indicated that lipocyte hyperplasia contributes to postmaturational increases in fat deposition.

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.