Middle-redox potential laccase from Ganoderma sp.: its application in improvement of feed for monogastric animals.

The variables influencing laccase production by white-rot fungus Ganoderma sp. rckk-02 were optimized employing response surface methodology. Malt extract (6.0% w/v), lignin (0.5% w/v) and pH (5.5) were found to be the most significant factors for enhanced laccase production by 7 fold (226.0 U/ml) as compared to unoptimized growth conditions (32.0 U/ml). The N-terminal sequence of laccase revealed its distinct amino acid profile (S- I- R- N- S- G), which suggested it as a novel enzyme. The Far-UV CD spectrum of the laccase showed single broad negative trough at around 213 nm, a typical signature of all ß proteins. The laccase was found to fall in the range of middle redox potential laccases. Purified laccase at dosage of 2.5 Ug(-1) body weight when supplemented with pelleted diet of rats, a significant improvement (p < 0.05) in nutrients digestibility without causing any elevation of blood stress enzymes was observed.

Nutritional and toxicological assessment of white-rot fermented animal feed.

The fungal fermented wheat straws as animal feeds have been evaluated for its toxicological and nutritional status in male rats (Holtzman strain). Digestibility of dry matter and other nutrients as well as fiber fractions were found significantly higher (P < 0.05) in straw fermented with either Ganoderma sp. rckk02 (T3) or Crinipellis sp. RCK-1 (T4) than unfermented straw (T1) or straw fermented with Pycnoporus cinnabarinus (T2). The aflatoxin B1, B2, G1 and G2 were either absent or present in permissive levels in T3 and T4 diets and exhibited normal stress enzyme activity in case of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) enzymes whereas, rats fed on T2 diet showed elevated levels of stress enzymes (ALT, AST and LDH activity), 100% high morbidity and 8.3% mortality. This study suggests that Ganoderma sp. rckk02 and Crinipellis sp. RCK-1 are efficient in improving the nutritive value of poor quality straw and do not posses any threat for their subsequent use as ruminant feed.

Performance of growing lambs fed processed karanj (Pongamia glabra) oil seed cake as partial protein supplement to soybean meal.

The aim of this study was to determine whether processed karanj (Pongamia glabra) oil seed cake can be used as a supplement to partially replace soybean meal (SBM). Male lambs (n = 24) of uniform body weight (12.88 +/- 0.15 kg) were equally allotted at random to a SBM-based control (CON) and three test concentrate mixtures, containing detoxified solvent extracted karanj cake (SKC) using three processing methods: water washing (WW), 2.5% lime (LM) and 0.4% binder (BN) treatment. The processed SKC replaced 50% nitrogen of SBM of CON. The respective concentrate mixtures were fed along with ad libitum chaffed oat (Avena sativa) straw for 196 days. Dry matter intake was significantly (p < 0.01) lower on WW, LM and BN. Apparent digestibility coefficient of nutrients was comparable, except for total carbohydrates, which was significantly (p < 0.01) lower in LM and BN. Total gain, average daily gain and feed: gain ratio was comparable (p > 0.05) between the CON and WW diets but significantly lower in LM and BN groups. Yield of greasy wool was lower (p < 0.05) in BN group. Comparable dry matter and nutrient (crude protein and total digestible nutrients) conversion efficiency was observed on CON and WW diet but the lambs on the LM and BN diets exhibited lower (p < 0.01) conversion efficiency. It is concluded that SKC after water washing could replace 50% of SBM nitrogen in protein supplementation.

Effect of phenolic monomers on biomass and hydrolytic enzyme activities of an anaerobic fungus isolated from wild nil gai (Baselophus tragocamelus).

AIMS: To test the anaerobic fungus, Piromyces sp. FNG5, for its tolerance to phenolic monomers released in the rumen by degradation of lignocellulosic poor-quality feeds. METHODS AND RESULTS: Effects of phenolic monomers on biomass and fibrolytic enzyme activities of a pure culture of lignocellulolytic anaerobic fungus (Piromyces sp. FNG5) isolated from faeces of wild nil gai (blue bull, Baselophus tragocamelus) were evaluated. There was a reduction in fungal biomass at 1 mm concentration of catechol with complete inhibition at 10 mm. p-Coumaric acid caused a reduction in biomass at 10 mm and no growth was observed above 20 mm concentration. The fungal isolate could tolerate up to 5 mm of ferulic acid without any reduction in biomass level, and was able to grow to some extent up to the highest level of ferulic acid tested (20 mm). Vanillic acid had no effect on biomass of the fungus even up to 50 mm level. The phenolic monomers varied in their potential to inhibit the secretion of carboxymethyl cellulase, xylanase, beta-glucosidase and acetyl esterase activities with catechol being the most inhibitory and vanillic acid being the least inhibitory. After 14 days of incubation, 38.49-65.14%p-Coumaric acid, 65.22-74.10% ferulic acid and 34.13-66.78% vanillic acid disappeared from the medium under anaerobic conditions. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: It is concluded that the anaerobic fungus Piromyces sp. FNG5 is tolerant to phenolic monomers and has ability to degrade them. Therefore, such anaerobic fungi may play an important role in fibre degradation in the rumen.