Project description:To determine whether and how warming affects the functional capacities of the active microbial communities, GeoChip 5.0 microarray was used. Briefly, four fractions of each 13C-straw sample were selected and regarded as representative for the active bacterial community if 16S rRNA genes of the corresponding 12C-straw samples at the same density fraction were close to zero.
Project description:Ahmad2017 - Genome-scale metabolic model
(iGT736) of Geobacillus thermoglucosidasius (C56-YS93)
This model is described in the article:
A Genome Scale Model of
Geobacillus thermoglucosidasius (C56-YS93) reveals its
biotechnological potential on rice straw hydrolysate
Ahmad Ahmada, Hassan B. Hartmanb, S.
Krishnakumara, David A. Fellb, Mark G. Poolmanb, Shireesh
Srivastavaa
Journal of Biotechnology
Abstract:
Rice straw is a major crop residue which is burnt in many
countries, creating significant air pollution. Thus,
alternative routes for disposal of rice straw are needed.
Biotechnological treatment of rice straw hydrolysate has
potential to convert this agriculture waste into valuable
biofuel(s) and platform chemicals. Geobacillus
thermoglucosidasius is a thermophile with properties specially
suited for use as a biocatalyst in lignocellulosic
bioprocesses, such as high optimal temperature and tolerance to
high levels of ethanol. However, the capabilities of
Geobacillus thermoglucosidasius to utilize sugars in rice straw
hydrolysate for making bioethanol and other platform chemicals
have not been fully explored. In this work, we have created a
genome scale metabolic model (denoted iGT736) of the organism
containing 736 gene products, 1159 reactions and 1163
metabolites. The model was validated both by purely theoretical
approaches and by comparing the behaviour of the model to
previously published experimental results. The model was then
used to determine the yields of a variety of platform chemicals
from glucose and xylose — two primary sugars in rice
straw hydrolysate. A comparison with results from a model of
Escherichia coli shows that Geobacillus thermoglucosidasius is
capable of producing a wider range of products, and that for
the products also produced by Escherichia coli, the yields are
comparable. We also discuss strategies to utilise arabinose, a
minor component of rice straw hydrolysate, and propose
additional reactions to lead to the synthesis of xylitol, not
currently produced by Geobacillus thermoglucosidasius. Our
results provide additional motivation for the current
exploration of the industrial potential of Geobacillus
thermoglucosidasius and we make our model publicly available to
aid the development of metabolic engineering strategies for
this organism.
This model is hosted on
BioModels Database
and identified by:
MODEL1703060000.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:Wheat straw grown cultures of T. reesei QM9414 were supplemented with 100 µM L-methionine and the genome wide gene expression monitored in order to find novel L-Methionine repressible genes.
Project description:The induction of genes in response to exposure of T. reesei to wheat straw was explored using genome-wide RNA-seq and compared to published RNA-seq data and model of how A. niger senses and responds to the lignocellulose. After 24 h of exposure to straw, transcript levels of known and predicted lignocellulose-degrading enzymes increased to around 8% of total cellular mRNA in T. reesei, which was much less when compared to A. niger. The bulk of enzymes used to deconstruct wheat straw is similar in both fungi. Other, non-plant cell wall-degrading enzymes which may aid in lignocellulose degradation were also uncovered in T. reesei and similar to those described in A. niger. Antisense transcripts were also shown to be present in T. reesei and their expession can be regulated by the respective growth condition. Triplicate samples of T. reesei cultivated in each of the three following conditions were taken: 1) After 48 h growth in glucose-based minimal media; 2) After transfer of mycelia from glucose-based media into media containing wheat straw as a sole carbon source and 3) 5 h after addition of glucose to straw cultures.
Project description:Many crop species have complex genomes, making the conventional pathway to associating molecular markers with trait variation, which includes genome sequencing, both expensive and time-consuming. We used a streamlined approach to rapidly develop a genomics platform for hexaploid wheat based on the inferred order of expressed sequences. This involved assembly of the transcriptomes for the progenitor genomes of bread wheat, the development of a genetic linkage map comprising 9495 mapped transcriptome-based SNP markers, use of this map to rearrange the genome sequence of Brachypodium distachyon into pseudomolecules representative of the genome organization of wheat and sequence similarity-based mapping onto this resource of the transcriptome assemblies. To demonstrate that this approximation of gene order in wheat is appropriate to underpin association genetics analysis, we undertook Associative Transcriptomics for straw biomass traits, identifying associations and even candidate genes for height, weight and width.