Effect of Volvariella volvacea cultivaton on the chemical composition of agrowastes

The Mushroom, Volvariella volvacea, was cultivated on various agrowastes. Maximum mycelia extensions were recorded in cotton waste (98.23 ± 0.1 mm) and a combination of rice husk and cotton waste (101.87 ± 0.4 mm). A decrease in moisture content resulted in significant increase percentagecrude protein content of mushroom-treated waste compared to the untreated. Moisture content decreased from 61.48 in the mushroom-treated groundnut shell to 51.20% in the untreated. Untreated Groundnut shell had crude protein of 3.61% while treated had 8.42%. Crude protein content of sorghumshaft increased from 2.51% in the untreated to 8.77% in treated waste. Similar trend was observed in the various waste combinations. While changes in crude fibre and ash content of treated and untreated wastes were not significant, mineral contents were observed to increase. Phosphorus and potassiumion content also increased in mushroom-treated samples

Microbial Quality and Sensory Properties of Ogiri Produced from Watermelon (Citrullus lanatus) Seed

The aim is to study the microorganisms involved in fermentation, their occurrence and the organoleptic properties of fermented watermelon (Citrullus lanatus) seeds. The watermelon seeds were dehulled, sorted, washed and boiled for 4 hours and fermented naturally for nine days. Microorganisms isolated from the fermenting watermelon seeds were Bacillus sp, Lactococcus sp, Pediococcus sp, Streptococcus sp, Micrococcus sp and Alcaligenes ps for bacterial, while the fungi obtained were Mucor sp, Rhizopus sp, Fusarium sp, Candida sp and Saccharomyces sp. The bacterial count increased from 4 x101 cfu/mL to 1.21 x 1010 cfu/mL while fungal count also increased from 8 x 101sfu/mL to 1.2 x 109sfu/mL during the period of fermentation. The pH and temperature increased from 6.3 to 8.7 and 29oC to 40oC respectively. The total titratable acidity decreased from 0.176% to 0.027%. The mean sensory characteristics value of fermented sample as scored by the panelist shows that the texture of the fermenting sample become softer as fermentation progressed. The aroma became more pungent with a strong ammonia odour responsible for the characteristic flavour and a darker colour of product. The overall acceptability of fermented sample was adjudged like very much while the sample bought from the market was adjudged like moderately

Safety and protective effect of Lactobacillus acidophilus and Lactobacillus casei used as probiotic agent in vivo

The protective effect of Lactobacillus acidophilus and Lactobacillus casei, isolated from fresh cow milk, was studied in vivo. Toxicological data of rat serum revealed that the Lactobacillus isolates had liver improvement functions. Serum alanine aminotransferase (ALT) activities of the rats dosed with Lactobacillus isolates alone were lower (15.50 and 18.27 iu/l) than the control. There was a reduction in the count of enterobacteria in rats dosed with L. casei after 3 days of feeding trials. Protection of the gastrointestinal tract (GIT) by these isolates was also observed. Histopathological data confirmed partial protection of the GIT in rats dosed with Lactobacillus isolates and simultaneously infected with Escherichia coli. L. casei was generally observed to have a better effect than L. acidophilus in terms of liver function improvement, anticholesterolaemic effect, and reduction of enterobacteria in the GIT. Key words: Probiotic, protection, Lactobacillus African Journal of Biotechnology Vol.2(11) 2003: 448-45

Antimicrobial activities of Vernonia tenoreana

The antimicrobial activity of Vernonia tenoreana was investigated. Crude extracts and solvent fractions of the leaf and bark of V. tenoreana were obtained using methanol and distilled water (2:3, v:v),ethylacetate, chloroform, and n-hexane as solvents of extraction. The crude and solvent fractions showed broad spectrum activities against Staphylococcus aureus, Streptococcus faecalis, Bacillussubtilis, B. cereus, Shigella dysenteriae, Klebsiella pneumonia, Pseudomonas aeruginosa and Proteus vulgaris, with zones of inhibition ranging from 1.7 to 18.3 mm. The leaf extracts showed betterantimicrobial activities, as the minimum inhibitory concentration (MIC) values for most of the isolates was 10 mg/ml with a least value of 5 mg/ml recorded for P. aeruginosa (NCIB 950). On the contrary, inthe case of bark extract, 15 mg/ml was the MIC value recorded for most of the test isolates with the least value of 10 mg/ml recorded for S. aureus, B. subtilis, and K. pneumoniae. Out of all the solventfractions, the chloroform fractions exhibited the highest antimicrobial activities. The bark extracts exercised antifungal activities against Candida albicans, Aspergillus niger and A. flavus, while the leafextract was inactive against all the fungal isolates. Phytochemical constituents revealed the presence of saponins, tannins, and anthraquinones in the bark extracts, while, tannins, anthraquinones, andcardenolides were present in the leaf extract

Impact of electromagnetic field on the pathogenicity of selected entomopathogenic bacteria (Proteus sp. and Bacillus sp.) on tick (Rhipicephalus decoloratus)

The effect of exposing entomopathogenic bacteria isolated from tick (Rhipicephalus decoloratus) to variable intensities of electromagnetic field for different periods of time was examined on their pathogenicity on tick. Some bacterial isolates from the macerate of tick cadavers were used in the infection of healthy engorged ticks. Two of the bacteria tested namely Proteus mirabilis and Bacillus cereus were able to induce morbid conditions in the ticks both of which were re-isolated from the resulting tick cadavers. Re-infection of different concentrations of both entomopathogenic bacteria of ticks were carried out on the tested ticks to determine the minimum lethal concentration required for pathogenicity. The result reveals that P. mirabilis and B. cereus were able to cause disease at concentrations of 106 and 107 cfu/ml, respectively. These bacteria were then exposed to electromagnetic field with different intensities for different periods of time after which they were reinfected into healthy insects. Conclusively, the study reveals some signs of stimulation in the entomopathogenic potency of B. cereus after exposure to electromagnetic field (EMF) when compared to the control treatments while a significant reduction in the  entomopathogenic potency of P. mirabilis was recorded.Keywords: Entomopathogens, electromagnetic field, Proteus mirabilis, Bacillus cereus.African Journal of Biotechnology Vol. 12(29), pp. 4683-469

Purification and characterization of pectinmethylesterase from Aspergillus repens isolated from cultivated soil

Aspergillus repens isolated from cultivated soils released pectinmethylesterase (PME) into the liquid culture medium during growth. The enzyme preparation was partially purified by ammonium sulphate precipitation and dialysed. The ammonium sulphate-dialysate fraction of the enzyme was separated by molecular exclusion and ion exchange chromatography. The molecular weight of the enzyme was found to be 141,300 daltons. The optimum temperature for PME activity was 30oC and most active at pH 6.5. The activity of the enzyme was stimulated by Na+, K+, Ca2+, Mg2+ and Zn2+, while EDTA, PbCl2, HgCl2 and IAA inhibited enzyme activity. The activity of the enzyme increased with increase in substrate concentration reaching maximum at 4 mg/ml. The Lineweaver-Burk plot for the hydrolysis of pectin indicated approximately 1.3 mg/ml. These qualities could be explored during the industrial applications of this enzyme

Effect of Cassia hirsuta (L) extract on DNA profile of some microorganisms

The effect of ethanol extract of leaf of Cassia hirsute (L) on the DNA profile of some selected pathogenic microorganisms were investigated using PCR-RAPD analysis to generate DNA fingerprint. The change in molecular configuration of organisms with and without extract shows a wide disparitybetween the sensitive and the resistant organism. Thus, this study demonstrates that some of the organisms are susceptible to the antimicrobial activity of C. hirsute extract while others are resistant

Comparative evaluation of the bacteria isolated from decomposing cow milk and soybean milk

A comparative evaluation of the bacteria isolated from decomposing cow milk and soybean milk were investigated. Six (6) bacterial species Bacillus circulans, Bacillus pumilus, Bacillus subtilis, Micrococcus luteus, Streptococcus faecalis and Streptococcus lactis were isolated from decomposing cow milk, while four (4) bacterial species namely Bacillus brevis, Bacillus licheniformis, Lactobacillus casei and Staphylococcus epidermidis were isolated from decomposing soybean milk stored at ambient temperature (30 + 10C). The initial bacterial load was found to be log 3.18 cfu/ml and log 3.70 cfu/ml in the decomposing cow milk and soybean milk respectively. The counts increased to log 9.99cfu/ml and 8.96 cfu/ml, in cow milk and soybean milk respectively, when the experiment was terminated. There was an increase from 40.0 to 90.0% occurrence of the bacterial isolates between day zero and day 4. Fresh cow milk contained 4.70% crude protein, 18.94% total solids and 0.0141% acidity; this values increased to 5.12 crude protein, 18.97% total solids and 0.1172% acidity in the spoilt sample while, fresh soybean milk contained 3.40% crude protein, 11.73% total solids and 0.0522% acidity, which also increased to 3.49% crude protein, 11.74% total solids and 0.0798% acidity in the spoilt sample on day 7. However, fresh cow milk was recorded to contain 9.75% soluble solids, 36.5mg/ml total sugar, and pH of 6.4; these values decreased to 7.67 soluble solids, 17.6mg/ml total sugar and pH of 3.9 in the spoilt sample while, fresh soybean milk was recorded to contain 9.60% soluble solids, 40.8%mg/ml total sugar and pH 6.2; this values also decreased to 5.69 soluble solids, 19.2mg/ml total sugar and pH 4.4 respectively on day 7, when the experiment was terminated. The 1.00 and 0.50% total ash with 3.50 and 2.75% crude fat recorded for the fresh cow milk and fresh soybean milk did not change in the spoilt samples throughout the study period.JARD Vol. 4 (2) 2005: pp. 122-13