An extended incubation strategy to culture slow growing members of anaerobic fungi resulted in the isolation of a novel anaerobic fungus from the rumen of a goat after 15 days. The novel genus, represented by type strain G1SC, showed filamentous monocentric thallus development and produced uniflagellate zoospores, hence, showing morphological similarity to the genera Piromyces, Buwchfawromyces, Oontomyces and Pecoramyces. However, strain G1SC showed genetic similarity to the genus Anaeromyces, which, though produces uniflagellate zoospore, also exhibits polycentric thallus development. Moreover, unlike Anaeromyces, strain G1SC did not show hyphal constrictions, instead produced a branched, determinate and anucleate rhizoidal system. This fungus also displayed extensive sporangial variations, both exogenous and endogenous type of development, short and long sporangiophores and produced septate sporangia. G1SC utilised various complex and simple substrates, including rice straw and wheat straw and produced H2, CO2, formate, acetate, lactate, succinate and ethanol. Phylogenetic analysis, using internal transcribed spacer 1 (ITS1) and D1/D2 domain of large-subunit (LSU) rRNA locus, clearly showed a separate lineage for this strain, near Anaeromyces. The ITS1 based geographical distribution studies indicated detection of environmental sequences similar (93–96%) to this strain from cattle faeces. Based on morphological and molecular characterisation results of strain G1SC, we propose a novel anaerobic fungus Liebetanzomycespolymorphusgen. et sp. nov., in the phylum Neocallimastigomycota.

Completely damaged wheat grains, unfit for human consumption, were fermented to H2 by Bacillus licheniformis strain JK1. Batch-culture fermentation of wheat slurries [6% (w/v) total solids and 5.8% (w/v) organic solids (OS)] evolved 225, 205 and 203 l of biogas-H, a mixture of H2, CO2 and H2S, per kg OS at pH 6, 7 and 8, respectively. H2 constituted 25% to 41% of the total biogas-H evolved. In single-stage continuous culture, H2 generated/kg OS reduced was 70 l at pH 6 and 74 l at pH 7 and 8.

Anaerobic fungi from the herbivore digestive tract (Neocallimastigomycetes) are primary lignocellulose modifiers and hold promise for biotechnological applications. Their molecular detection is currently difficult due to the non-specificity of published primer pairs, which impairs evolutionary and ecological research with environmental samples. We developed and validated a Neocallimastigomycetes-specific PCR primer pair targeting the D2 region of the ribosomal large subunit suitable for screening, quantifying, and sequencing. We evaluated this primer pair in silico on sequences from all known genera, in vitro with pure cultures covering 16 of the 20 known genera, and on environmental samples with highly diverse microbiomes. The amplified region allowed phylogenetic differentiation of all known genera and most species. The amplicon is about 350 bp long, suitable for short-read high-throughput sequencing as well as qPCR assays. Sequencing of herbivore fecal samples verified the specificity of the primer pair and recovered highly diverse and so far unknown anaerobic gut fungal taxa. As the chosen barcoding region can be easily aligned and is taxonomically informative, the sequences can be used for classification and phylogenetic inferences. Several new Neocallimastigomycetes clades were obtained, some of which represent putative novel lineages such as a clade from feces of the rodent Dolichotis patagonum (mara).

Viable cells of H2-producers (Bacillus licheniformis and a mixed microbial culture) were immobilized on brick dust and in calcium alginate beads. In batch culture, cells of the mixed culture in the free state yielded 8.2 l H2/mol glucose utilized, whereasB. licheniformis evolved 13.1 l H2. Immobilized cells, however, gave 4-fold more H2 than the free bacteria. Highest yields were from the cells immobilized on brick dust. High H2-production rates continued over two rounds of re-use of the immobilized cells.

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