Isolation of natural cultures of anaerobic fungi and indigenously associated methanogens from herbivores and their bioconversion of lignocellulosic materials to methane

Jin, Wei; Cheng, Yanfen; Mao, Shengyong; Zhu, Weiyun

doi:10.1016/j.biortech.2011.06.026

Cited by 72 publications

(95 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most abundant Methanobrevibacter gottschalkii and Methanobrevibacter ruminantium OTUs shared high sequence identity with strains isolated from camel feces (36), which indicates that these OTUs may be widely spread among different host species. Similarly, the most abundant Methanomassiliicoccales OTU identified in this study has also been identified in different host species and in a variety of geographic locations around the world.…”

Section: Discussionmentioning

confidence: 93%

Few Highly Abundant Operational Taxonomic Units Dominate within Rumen Methanogenic Archaeal Species in New Zealand Sheep and Cattle

Seedorf

Kittelmann

Janssen

2015

Appl Environ Microbiol

View full text Add to dashboard Cite

Sequencing and analyses of 16S rRNA gene amplicons were performed to estimate the composition of the rumen methanogen community in 252 samples from eight cohorts of sheep and cattle, separated into 16 different sample groups by diet, and to determine which methanogens are most prominent in the rumens of farmed New Zealand ruminants. Methanobacteriales (relative abundance ؎ standard deviation, 89.6% ؎ 9.8%) and Methanomassiliicoccales (10.4% ؎ 9.8%) were the two major orders and contributed 99.98% (؎0.1%) to the rumen methanogen communities in the samples. Sequences from Methanobacteriales were almost entirely from only four different species (or clades of very closely related species). Each was detectable in at least 89% of the samples. These four species or clades were the Methanobrevibacter gottschalkii clade and Methanobrevibacter ruminantium clade with a mean abundance of 42.4% (؎19.5% standard deviation) and 32.9% (؎18.8%), respectively, and Methanosphaera sp. ISO3-F5 (8.2% ؎ 6.7%) and Methanosphaera sp. group5 (5.6% ؎ 5.7%). These four species or clades appeared to be primarily represented by only one or, in one case, two dominant sequence types per species or clade when the sequences were grouped into operational taxonomic units (OTUs) at 99% sequence identity. The mean relative abundance of Methanomassiliicoccales in the samples was relatively low but exceeded 40% in some of the treatment groups. Animal feed affected the apparent methanogen community structure of both orders, as evident from differences in relative abundances of the major OTUs in animals under different feeding regimens.M ethane is the second most significant anthropogenic greenhouse gas, after carbon dioxide, and its concentration in the atmosphere is increasing (1). One major contributor to this is an intensification and expansion of global agricultural activities, in particular increased ruminant livestock numbers. Ruminants, such as cattle, sheep, and domesticated deer, produce large amounts of methane via enteric fermentation and are the most numerous farm animals in New Zealand. It is estimated that methane from these animals accounts for almost 30% of New Zealand's total anthropogenic greenhouse gas emissions (2).Methane is produced in the rumen by methanogenic archaea, here referred to as methanogens. Methanogens comprise a phylogenetically diverse group of microorganisms that are present in the rumen at up to ϳ10 10 cells/g rumen contents (3). Previous analyses have shown that members of the orders Methanobacteriales and Methanomassiliicoccales are dominant in the rumens of domesticated ruminants in New Zealand and many other geographic locations around the world (4). The order name Methanomassiliicoccales has only recently been proposed (5). These methanogens are closely related to the Thermoplasmatales (6) and were previously known as rice cluster III (RC-III) archaea (7), rumen cluster C (RCC) (4), or Methanoplasmatales (8). Within the order Methanobacteriales, hydrogenotrophic methanogens of the genus Methanobrevibacter appe...

show abstract

Section: Discussionmentioning

confidence: 93%

Few Highly Abundant Operational Taxonomic Units Dominate within Rumen Methanogenic Archaeal Species in New Zealand Sheep and Cattle

Seedorf

Kittelmann

Janssen

2015

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…Our previous studies showed that some rumen methanogens were indigenously associated with anaerobic fungi, which could result in a strong degradation of lignocellulosic materials [18,19]. Through an approach using a co-culture derived from a mixed-culture, our study further found that a novel species belonging to RCC grew in the anaerobic fungal subcultures.…”

Section: Introductionmentioning

confidence: 51%

“…Recent studies showed that methanogens belonging to this group [8,14-17] could strictly use hydrogen to reduce methanol and methylamines to methane. It is well known that both anaerobic fungi and protozoa could produce hydrogen, which is one of the substrates for methanogens [19,21]. This may make it possible for anaerobic fungi to provide RCC species with hydrogen.…”

Section: Discussionmentioning

confidence: 99%

“…Fungal colonies containing the novel RCC species were purified from the mixed culture, according to our previous study [19]. Briefly, an aliquot of 0.5 ml of 10 −1 to 10 −3 diluted mixed culture was inoculated into 5 ml media with agar in Hungate roll-tube and incubated at 39°C in the incubator (PYX-DHS-50 × 65, Shanghai, China) without shaking.…”

Section: Methodsmentioning

confidence: 99%

“…Methane was detected by GC (Shimadzu, gas chromatograph GC-14 B, Japan) according to the method described in our previous study [19]: capillary column (Supelco, Column No. 41491-03B, US) temperature 80°C, vaporizer temperature 100°C, flame ionization detector temperature 120°C, carrier gas (N 2 ) pressure 0.05 MPa, H 2 pressure 0.05 MPa and air pressure 0.05 MPa.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Discovery of a novel rumen methanogen in the anaerobic fungal culture and its distribution in the rumen as revealed by real-time PCR

et al. 2014

Self Cite

View full text Add to dashboard Cite

BackgroundThe novel archaea belonging to Rumen Cluster C (RCC), which may play an important role in methane production in the rumen have received increased attention. However, the present information on RCC in the rumen is limited by the unsuccessful isolation of axenic pure RCC from the rumen. In the present study, RCC grown in anaerobic fungal subcultures was identified by the molecular and culture methods.ResultsA novel RCC species existing in the fungal subcultures was identified and demonstrated by the 16S rRNA gene clone library. Interestingly, the novel RCC species survived in the fungal cultures over all the subculture transferring, even in the 62nd subculture, in contrast to the other methanogens, which disappeared during subcultures. Further work showed that subculture transfer frequency significantly affected the relative abundance of the novel RCC species in the fungal subcultures. The five-day and seven-day transfer frequencies increased the relative abundance of the RCC species (P<0.05). In addition, quantitative real-time PCR revealed that high concentrate diets did not affect the abundance of archaea, but numerically reduced the abundance of the novel RCC species in the rumen. In addition, the relative abundance of the RCC species was numerically higher in the rumen liquid fraction than in the rumen epithelium and solid fractions. Finally, a purified fungal culture containing the RCC species was successfully obtained. PCR and sequencing analysis showed that the novel RCC species contained a mcrA gene, which is known to play a crucial role in methanogenesis, and thus could be identified as a methanogen.ConclusionIn this study, a novel RCC species was identified as a methanogen and closely associated with anaerobic fungi. This novel approach by using co-culture with anaerobic fungi may provide a feasible way to culture and investigate not yet identified methanogens.

show abstract

Indigenously associated methanogens intensified the metabolism in hydrogenosomes of anaerobic fungi with xylose as substrate

Jin

et al. 2017

J Basic Microbiol

Self Cite

View full text Add to dashboard Cite

Anaerobic fungi are potent lignocellulose degraders, but have not yet been exploited in this capacity, largely owing to their poor metabolic characterization. In the current study, a time course of fermentation was conducted to study the effect of the co-cultured methanogens on xylose metabolism by anaerobic fungi. The fermentation end-products from anaerobic fungal monoculture were H (6.7 ml), CO (65.7 ml), formate (17.90 mM), acetate (9.00 mM), lactate (11.89 mM), ethanol, and malate after 96 h fermentation. Compared to the monoculture, the end-products of co-culture shifted to more CO (71.8 ml) and acetate (15.20 mM), methane (14.9 ml), less lactate (5.28 mM), and hardly detectable formate and H at the end of fermentation. After 48 h, accumulated formate was remarkably consumed by co-cultured methanogens, accompanied by significantly increased acetate, CO and pH, and decreased lactate and malate. Xylose utilization, in both cultures, was similar during fermentation. However, the relative flux of carbon in hydrogenosomes in the co-culture was higher than that in the monoculture. In conclusion, the co-culture with methanogens enhanced "energy yields" of anaerobic fungi by removing the accumulated formate, decreased the metabolism in cytosol, for example, the lactate pathway, and increased the metabolism in hydrogenosomes, for example, the acetate pathway.

show abstract

Isolation of natural cultures of anaerobic fungi and indigenously associated methanogens from herbivores and their bioconversion of lignocellulosic materials to methane

Cited by 72 publications

References 27 publications

Few Highly Abundant Operational Taxonomic Units Dominate within Rumen Methanogenic Archaeal Species in New Zealand Sheep and Cattle

Few Highly Abundant Operational Taxonomic Units Dominate within Rumen Methanogenic Archaeal Species in New Zealand Sheep and Cattle

Discovery of a novel rumen methanogen in the anaerobic fungal culture and its distribution in the rumen as revealed by real-time PCR

Indigenously associated methanogens intensified the metabolism in hydrogenosomes of anaerobic fungi with xylose as substrate

Contact Info

Product

Resources

About