Fermentation activities of some new species of anaerobic rumen fungi from Malaysia.

Abstract

The fermentation activities of three new anaerobic rumen fungi, viz, Neocallimastix variabilis, Piromyces spiralis and P. minutus, and a Caecomyces communis isolate grown on straw and filter paper media were studied. N. variabilis, P. spiralis and P. minutus produced carboxymethylcellulase (CMCase), FPase (filter paper activity) and xylanases when grown on straw and filter paper media. C. communis produced only xylanases. The maximum production of all the enzymes was at 72 h of fungal incubation. On both media, N. variabilis showed the highest enzyme activities, followed by P. spiralis and P. minutus. Specific enzyme activities of the three fungal isolates in descending order of production were: Xylanase > CMCase > FPase when grown on straw medium; and CMCase > Xylanase > FPase > cellobiase when grown on filter paper medium. The major end-products of fermentation by the three new fungal isolates were acetate and formate. Ethanol and succinate were produced in low amounts and lactate was not detected. The absence of lactate in the end-products of fermentation observed in this study is the first such report.Anaerobic fungi produce a range of polysaccharide-degrading enzymes such as cellulases, hemicellulase and xylanases to degrade plant structural materials. The cellulases produced by the fungi consist of a complex of enzymes capable of solubilising both the amorphous and crystalline cellulose present in plant tissues. Neocallimastix frontalis, N. patriciarum, Piromyces communis and a Piromyces sp. have been found to release large amounts of endo-l,4-glucanase (CMCase) into the culture supernatants (17,23). Exo-1,4 /3-D-glucanase (cellobiohydrolases) which

Anaerobic rumen fungi and fungal direct-fed microbials in ruminant feeding

“…In general, polycentric anaerobic fungi produce less lactate compared to monocentric organisms (Gordon and Phillips, 1993). However, some studies reported that Piromyces present in the rumen did not generate any lactate (Ho et al, 1996). Some ARF species were reported to produce an endo-pectin lyase and polygalacturonase (Gordon and Phillips, 1993).…”

Molecular identification of anaerobic fungi isolated from buffalo rumen with their growth rate, cellulase enzyme activity, and fermentation products characteristics

“…Similarly, Nagpal et al (2009) reported that the FPase enzyme in Caecomyces sp. was higher activity than CMCase, while Ho et al (1996) stated that Filter Paper was pure cellulose which can induce anaerobic fungi to produce enzymes, especially cellulase. The results also showed that all anaerobic fungi isolated from buffalo rumen had the lowest Avicel hydrolysis activity compared to other substrates.…”

“…The results in Figure 2 showed that all anaerobic fungi isolated from the rumen of buffalo have increased activity of cellulase (CMCase, Avicelase, and FPase) after passing through the growth lag phase (24 hours). The results of a study conducted by Ho et al (1996) showed that the CMCase and FPase activity of anaerobic fungi types N. variabilis, P. spiralis, P. minutus, and C. communis also increased rapidly after 24 hours. The results also showed that all anaerobic fungi reached optimum conditions at 5 days because the peak of fungal growth occurred at 96-108 hours (4-4.5 days) and enzyme activity was measured every 24 hours.…”

“…Edwards et al (2017) stated that anaerobic fungi have a major role in the degradation process of lignocellulose in feed. They can produce enzymes to degrade fibers such as cellulase, hemicellulase, as well as xylanase (Ho et al 1996), and also penetrate feed particles using rhizoids (Ho and Barr 1995;Kittelmann et al 2012;Solomon et al 2016). Anaerobic fungi can produce xylanase, mannanase, galactanase, exoglucanase, endoglucanase and βglucosidase wich plays an important role for feed fiber degradation (Chen et al 2012;Youssef et al 2013;Wang et al 2014;Ma et al 2022).…”