Comparison of growth characteristics of anaerobic fungi isolated from ruminant and non-ruminant herbivores during cultivation in a defined medium

Abstract

Anaerobic fungi were isolated from rumen fluid of a domestic sheep (Onis aries; a ruminant) and from faeces of five non-ruminants: African elephant (Loxodonta africana), black rhinoceros (Diceros bicornis), Indian rhinoceros (Rhinoceros unicornis), Indian elephant (Elephas maximus) and mara (Dolichotis patagonum). The anaerobic fungus isolated from the sheep was a Neocallimastix species and the isolates from non-ruminants were all species similar to Piromyces spp. A defined medium is described which supported growth of all the isolates, and was used to examine growth characteristics of the different strains. For each fungus the lipid phosphate content was determined after growth on cellobiose and the resulting values were used to estimate fungal biomass after growth on solid substrates. The ability of isolates from ruminants and non-ruminants to digest both wheat straw and cellulose was comparable. More than 90% and 60%, respectively, of filter paper cellulose and wheat straw were digested by most strains within 60-78 h. Growth of two fungi, isolated from rumen fluid of a sheep (Neocallimastix strain N1) and from faeces of an Indian rhinoceros (Pivomyces strain Rl), on cellobiose was studied in detail. Fungal growth yields on cellobiose were 64.1 g (mol substrate)-' for N1 and 34.2 g mol-l for R1. The major fermentation products of both strains were formate, lactate, acetate, ethanol and hydrogen.

Characterization of an anaerobic fungus from Ilama faeces

“…Anaerobic fungi isolated from hindgut fermenters were assigned to other genera, i.e. Caecomyces (Gold et al, 1988) and Piromyces (Teunissen et al, 1991). However, the isolation of a Neocallimastix strain from the tapir (Tapirus terrestris), a hindgut fermenter (F. D. Marvin-Sikkema, unpublished), suggests that the genus Neocallimastix is not restricted to foregut-fermenting herbivores.…”

“…The organism was subcultured every 2-3 d in order to avoid cell death. Stock cultures were preserved as described by Teunissen et al (1991).…”

“…Anaerobic fungi inhabit certain regions of the alimentary tract of many herbivorous mammals (Orpin & Joblin, 1988;Teunissen et al, 1991). The importance of anaerobic fungi in herbivore digestion remains unclear, but their capacity to produce large amounts of fibredigesting enzymes (Williams & Orpin, 1987) and their ability to digest up to half of the dry weight of plant tissue in uitro (Lowe et al, 1987) suggest that they contribute significantly to plant fibre digestion in herbivores.…”

In Silico Identification of Microbial Partners to Form Consortia with Anaerobic Fungi

“…Gas accumulation in the head space of the starter cultures was vented daily. All experiments were conducted in triplicate using 40 mL of M2 media [18] loaded with 2 g of corn stover grass, (4 mm particle size) supplied by the USDA-ARS research center (Madison, WI, USA), in 75 mL serum bottles.…”

Paenibacillus curdlanolyticus Strain B-6 Multienzyme Complex: A Novel System for Biomass Utilization

“…Cellulosomes are produced mainly by anaerobic bacteria, mostly from the class clostridia, and some anaerobic fungi such as genus Neocallimastix (Dalrymple et al, 1997), Piromyces (Teunissen et al, 1991) and Orpinomyces (Li et al, 1997). However, evidence suggests the presence of cellulosomes or cellulosome-like multienzyme complexes in a few aerobic microorganisms (Table 1).…”