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Characterization of wheat straw-degrading anaerobic alkali-tolerant mixed cultures from soda lake sediments by molecular and cultivation techniques.

Porsch K, Wirth B, Tóth EM, Schattenberg F, Nikolausz M - Microb Biotechnol (2015)

Bottom Line: Methanothermobacter and Methanosarcina genera and the order Methanomicrobiales were predominant methanogenes in the obtained cultures.Additionally, single cellulolytic microorganisms were isolated from enrichment cultures and identified as members of the alkaliphilic or alkalitolerant genera.The results show that anaerobic alkaline habitats harbor diverse microbial communities, which can degrade lignocellulose effectively and are therefore a potential resource for improving anaerobic digestion.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioenergy, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.

No MeSH data available.


Related in: MedlinePlus

n-MDS plot based on Bray–Curtis dissimilarity index showing the similarity relationships of the microbial communities in enrichment steps obtained from (A and B) the Lake Szarvas (denoted with S) and from (C) Lake Velencei (denoted with V). The analysis is based on the T-RFLP data obtained by MspI restriction enzyme. The ellipses show the 95% confidence interval. Sed – original sample; En – first enrichment step; 1–9.T – further transfer steps; 37 and 55 – incubation temperature [°C].
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fig02: n-MDS plot based on Bray–Curtis dissimilarity index showing the similarity relationships of the microbial communities in enrichment steps obtained from (A and B) the Lake Szarvas (denoted with S) and from (C) Lake Velencei (denoted with V). The analysis is based on the T-RFLP data obtained by MspI restriction enzyme. The ellipses show the 95% confidence interval. Sed – original sample; En – first enrichment step; 1–9.T – further transfer steps; 37 and 55 – incubation temperature [°C].

Mentions: The bacterial community carries out the first three steps of the biogas process (hydrolysis, acidogenesis and acetogenesis), whereas Archaea are responsible for the last step, the methanogenesis (Weiland, 2010). The bacterial community of the sediment samples, the initial enrichment and the following transfers of the cultures V37°C, S37°C and S55°C were characterized by T-RFLP. In comparison to the sediment samples, the community structure had been significantly changed during the first enrichment step of all three cultures. This is not surprising since the cultivation medium and temperature did not correspond to the conditions in the lake sediments. Based on the statistical analysis of the dissimilarity values between the T-RFLP profiles of the samples, the non-metric multidimensional scaling (n-MDS) ordination analysis grouped the transfers together, while the original sediment samples and the first enrichment step in case of the thermophilic enrichment were outliers (Fig. 2A–C). In contrast, the first enrichment step has already resulted in a similar community structure to the further transfers at 37°C. These results supports the physiological data by showing that transferring the cultures several times have not influenced the microbial community (and their activity) to a great extent. Deoxyribonucleic acid (DNA) was also isolated from few of the controls at 37°C and at 55°C. The DNA yield was negligible, and polymerase chain reaction (PCR) amplification was difficult. In that case, DNA probably originated from dead cells or microbes growing from spores survived the autoclaving. The T-RFLP patterns of the controls were not similar to those obtained from the transfers (data not shown).


Characterization of wheat straw-degrading anaerobic alkali-tolerant mixed cultures from soda lake sediments by molecular and cultivation techniques.

Porsch K, Wirth B, Tóth EM, Schattenberg F, Nikolausz M - Microb Biotechnol (2015)

n-MDS plot based on Bray–Curtis dissimilarity index showing the similarity relationships of the microbial communities in enrichment steps obtained from (A and B) the Lake Szarvas (denoted with S) and from (C) Lake Velencei (denoted with V). The analysis is based on the T-RFLP data obtained by MspI restriction enzyme. The ellipses show the 95% confidence interval. Sed – original sample; En – first enrichment step; 1–9.T – further transfer steps; 37 and 55 – incubation temperature [°C].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4554468&req=5

fig02: n-MDS plot based on Bray–Curtis dissimilarity index showing the similarity relationships of the microbial communities in enrichment steps obtained from (A and B) the Lake Szarvas (denoted with S) and from (C) Lake Velencei (denoted with V). The analysis is based on the T-RFLP data obtained by MspI restriction enzyme. The ellipses show the 95% confidence interval. Sed – original sample; En – first enrichment step; 1–9.T – further transfer steps; 37 and 55 – incubation temperature [°C].
Mentions: The bacterial community carries out the first three steps of the biogas process (hydrolysis, acidogenesis and acetogenesis), whereas Archaea are responsible for the last step, the methanogenesis (Weiland, 2010). The bacterial community of the sediment samples, the initial enrichment and the following transfers of the cultures V37°C, S37°C and S55°C were characterized by T-RFLP. In comparison to the sediment samples, the community structure had been significantly changed during the first enrichment step of all three cultures. This is not surprising since the cultivation medium and temperature did not correspond to the conditions in the lake sediments. Based on the statistical analysis of the dissimilarity values between the T-RFLP profiles of the samples, the non-metric multidimensional scaling (n-MDS) ordination analysis grouped the transfers together, while the original sediment samples and the first enrichment step in case of the thermophilic enrichment were outliers (Fig. 2A–C). In contrast, the first enrichment step has already resulted in a similar community structure to the further transfers at 37°C. These results supports the physiological data by showing that transferring the cultures several times have not influenced the microbial community (and their activity) to a great extent. Deoxyribonucleic acid (DNA) was also isolated from few of the controls at 37°C and at 55°C. The DNA yield was negligible, and polymerase chain reaction (PCR) amplification was difficult. In that case, DNA probably originated from dead cells or microbes growing from spores survived the autoclaving. The T-RFLP patterns of the controls were not similar to those obtained from the transfers (data not shown).

Bottom Line: Methanothermobacter and Methanosarcina genera and the order Methanomicrobiales were predominant methanogenes in the obtained cultures.Additionally, single cellulolytic microorganisms were isolated from enrichment cultures and identified as members of the alkaliphilic or alkalitolerant genera.The results show that anaerobic alkaline habitats harbor diverse microbial communities, which can degrade lignocellulose effectively and are therefore a potential resource for improving anaerobic digestion.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioenergy, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.

No MeSH data available.


Related in: MedlinePlus