Open Access Original Research Article

Microbial Biodegradation of Aromatic Compounds in a Soil Contaminated with Gasohol

A. G. Parreira, M. R. Tótola, G. N. Jham, S. L. Da Silva, A. C. Borges

Biotechnology Journal International, Page 18-28
DOI: 10.9734/BBJ/2011/295

The studies developed in this work aimed to find alternatives to biodegradation or bioremediation of soils contaminated with gasoline or gasohol. So, the biodegradation of benzene, toluene and o-xylene (BTX) in soil samples contaminated with gasoline or gasohol by a bacterial consortium was studied. Four bacterial strains were selected for the consortium based on their growth capacity in gasoline, gasohol and BTX as sole carbon sources, and on the production of biosurfactants in mineral medium containing gasohol as the sole carbon source. The reduction of BTX concentrations in soil slurries in a multi-cell bioreactor system was used as the criterion to evaluate biodegradation efficiency. BTX removal was highly stimulated by air injection and mineral nutrients, and was significantly increased by the presence of the bacterial consortium. Addition of a proprietary oxygen release compound did not stimulate the biodegradation of BTX.

Open Access Original Research Article

Study of Microbial Population and Enzyme Activities in Intercropped Peanut Rhizosphere with Different Nutrient Application

P. B. S. Bhadoria, M. Basu, S. C. Mahapatra

Biotechnology Journal International, Page 29-45
DOI: 10.9734/BBJ/2011/358

The aim of this study was to investigate the effect of different levels of chemical fertilizers (CF) alone or in combination with farmyard manure (FYM) under lime or no lime amelioration on biological properties of the rhizosphere soil of peanut, grown as intercrop with sabai grass (Eulaliopsis binata (Retz.) C.E. Hubb) in an acid lateritic soil. The effect of five fertilization levels viz., no CF (F0), CF @ 20:40:30 (F1), CF @ 40:80:60 (F2) kg ha-1 NPK, F1 + 2.5 t FYM ha-1 (F3) and F2 + 5 t FYM ha-1 (F4) with (2 t ha-1) and without lime application were studied on the bacterial density, dehydrogenase and phosphatase enzyme activities (i.e. acid and alkaline phosphomonoesterases), nitrogen accumulation in nodules and phosphorus solubilizing power at 25, 50, 75 and 100 days after sowing of peanut for two years. Results showed significant effects of fertilization levels and growth stages of the crop on the microbial activities. Populations of symbiotic nitrogen fixing and phosphorus solubilizing bacteria, soil enzyme activities, nitrogen accumulation in nodules and phosphorus solubilizing power in the FYM+CF treated plots significantly increased compared to sole CF treatments under both lime and no lime application. Lime application improved the activity of dehydrogenase and alkaline phosphomonoesterase enzymes, while decreased acid phosphomonoesterase activity. This study revealed that integrated application of optimum level of inorganic fertilizer, farmyard manure along with lime could improve the biological properties of an acid lateritic soil as well as the growth of peanut under sabai grass-peanut intercropping system.

Open Access Original Research Article

Effect of Cocktail of Fungi Blend on the Digestibility Coefficient and Digestible Nutrients of Goat (Capra hircus)

M. A. Belewu, K. Y. Belewu, L. A. Popoola

Biotechnology Journal International, Page 46-52
DOI: 10.9734/BBJ/2011/235

Nine West African dwarf goats (3 goats per diet) initially averaging between 4.5 and 6.5kg body weight, were fed either Jatropha curcas untreated diet A (control), 50% cocktail of fungi blend treated Jatropha curcas kernel cake (diet B) and 100% cocktail of fungi blend treated Jatrpoha curcas kernel cake (diet C) adlibitum for 56 days followed by a 7 day total faecal collection. All the diets have a crude protein content of between 17.99 and 19.23%. Total dry matter intake (TDMI) (543.25 – 606.25g/d) showed significant differences among the diets (p<0.05). The digestibility coefficient of dry matter which was similar (p>0.05) among the diets ranged between 91.84% and 94.31%. The digestibility of crude protein was numerically highest for diet B and least for other diets (A and C). The digestible dry matter intake was significantly (p<0.05) higher for diet B compared to other diets. The digestibility of crude fibre and ether extract followed same trend as other nutrients. The digestible crude protein intake was 481.6g/d (A), 544.63g/d (B) and 472.6g/d (C). The digestible crude fibre intake was greater (p<0.05) for diet B (576.25) followed closely by diet A (520.5g/d) and C (516.75g/d). Digestible ether extract intake tended (p<0.05) to be lower for goat fed diet C (500.00g/d) compared with diet A and diet B which were similar (p>0.05). In conclusion, inclusion of cocktail of fungi blend Jatropha curcas kernel cake in a mixed ration appear to be viable feed ingredient for goat diet.