Regulation of Cellulase and Hemicellulase Gene Expression in Fungi

Amore, Antonella; Giacobbe, Simona; Faraco, Vincenza

doi:10.2174/1389202911314040002

Cited by 202 publications

(178 citation statements)

References 200 publications

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“…Irfan et al (2011) documented glucose as the best additional carbon source while producing CMCase from Aspergillus sp. It is evident from various research studies that the cellulolytic systems in different fungi are induced to different levels in the presence of diverse sources of carbon (Amore et al 2013). The presence of an easily utilizable form of carbon, supportive for the growth of the fungus, may not be inductive for high cellulase production by the same fungal species (Tong and Rajendra 1992).…”

Section: Effect Of Carbon Sourcesmentioning

confidence: 99%

Enzymatic saccharification of pretreated rice straw by cellulases from Aspergillus niger BK01

et al. 2017

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Alkali-assisted acid pretreated rice straw was saccharified using cellulase from Aspergillus niger BK01. The cellulase production by the fungus was enhanced by parametric optimization using solid-state fermentation conditions. Maximum cellulase production (12.0 U/gds of carboxymethyl cellulase, CMCase) was achieved in 96 h, using 6.0% substrate concentration, 7.5% inoculum concentration, 1:2 solid to liquid ratio, at pH 5.5, and temperature 28°C, by supplementation of the fermentation medium with 0.1% carboxymethylcellulose and 0.1% ammonium nitrate. Characterization of crude cellulases showed that highest CMCase activity was observed at pH 4.8 and temperature 40°C. The CMCase was stable from pH 4.8-5.5 and at a temperature range of 35-50°C. The pretreated biomass was subjected to hydrolysis with the fungal cellulases. The saccharification optimization studies showed that 2% (v/v) enzyme concentration and hydrolysis time of 2.5 h were optimum for maximum yield, i.e, 23.78% sugars and 35.96% saccharification value.

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Section: Effect Of Carbon Sourcesmentioning

confidence: 99%

Enzymatic saccharification of pretreated rice straw by cellulases from Aspergillus niger BK01

et al. 2017

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“…This indicates that certain classes of genes, such as those involved in pathogenicity and secondary metabolite production, may be subject to increased selection pressures in L. maculans. Furthermore, the metabolic genes that showed PAV read hits, including aspartate aminotransferase, cellulase and fatty acid synthase, belong to multi-domain families which exhibit complex functional redundancy (Amore et al, 2013;Lal et al, 2014;Schweizer and Hofmann, 2004). This may allow for the function of these genes to be complemented by other genes within the pathway.…”

Section: Pav Read Hits To Gene Annotationsmentioning

confidence: 99%

Understanding the structure and variation within the genome of the pathogenic ascomycete fungus Leptosphaeria maculans

Zander¹

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The ascomycete fungus Leptosphaeria maculans is a major pathogen of Brassica species, particularly canola (Brassica napus; rapeseed; oil-seed rape), and the primary cause of crop losses of canola in Australia, causing blackleg disease. L. maculans, a filamentous ascomycete, is the causal agent of phoma stem canker, commonly referred to as blackleg.In late stages of infection, it spreads through the stem vasculature causing lesions, leading to poor growth, lodging and eventually plant death. This fungus is found in canola-growing regions worldwide such as Australia, Canada and Europe. Increased production of canola in these regions has led to a rise in the severity of the disease. In Australia alone, L. maculans infection is responsible for an estimated Australian $100 million in crop losses each year, with average losses ranging from 15-48 % and significant efforts are underway to improve resistance to this disease.Understanding the characteristics of L. maculans is vital for developing an effective and sustainable approach to the management of blackleg disease on Brassica species. The completion of the L. maculans genome sequence was a significant development in the study of this fungal pathogen and provides a reference genome to which molecular markers can be physically mapped. This has been highly useful in other plant pathogens with sequenced genomes, such as the wheat pathogen Parastagonospora nodorum and the cereal pathogen Fusarium graminearum. Importantly, a reference genome also allows mapping of whole genome re-sequencing data, which is becoming a high-throughput, costeffective method to study genome-wide diversity, particularly for the relatively small, lower complexity genomes of many fungal species. By re-sequencing the genome of different L. maculans isolates, variations in genome sequence and structure can be elucidated.Advances in genome sequencing technologies have revolutionised plant and fungal genomics. They have made genome sequencing, re-sequencing and Single Nucleotide Polymorphism (SNP) discovery highly accessible, high-throughput and cost-effective. The process of whole genome re-sequencing involves aligning millions of short sequence reads to a reference genome sequence. Once this has been achieved, it is possible to identify genetic variation between individuals, which can be linked to variation in phenotype to provide molecular genetic markers and insights into gene function.Sequence variation can have a major impact on how an organism develops and responds to the environment. III | P a g eThis thesis describes the implementation of several approaches to elucidating the genome structure and variation of a number of L. maculans isolates, including SNPs and presence/absence variations (PAVs).Initially, the re-sequencing of two L. maculans isolates for the identification of 21,814 SNPs was performed. I demonstrated the application of a novel SNP calling method, SGSautoSNP and its robustness and sensitivity in identifying polymorphisms in L.maculans. I described the use of these S...

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“…There can be different small molecule inducers of the same or similar CAZyme-encoding genes in different fungal species. A recent review by Amore et al [11] summarises many of these inducers and the genes that they induce in filamentous fungi. Other reviews also summarises some of the relevant inducers and induction mechanisms [13,29].…”

Section: Inducers and Induction Mechanismsmentioning

confidence: 99%

“…This chapter will focus on the ascomycetes. There are already several extensive reviews related to the regulatory responses of fungi to small molecules as well as, but less so, to lignocellulose [9,[11][12][13][14][15][16][17][18]. We will therefore refer to the reviewed information where applicable and expand the discussion to focus on exposure of fungi to lignocellulose.…”

Section: Introductionmentioning

confidence: 99%

Transcriptional Regulation and Responses in Filamentous Fungi Exposed to Lignocellulose

2015

Mycology: Current and Future Developments

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Biofuels derived from lignocellulose are attractive alternative fuels but their production suffers from a costly and inefficient saccharification step that uses fungal enzymes. One route to improve this efficiency is to understand better the transcriptional regulation and responses of filamentous fungi to lignocellulose. Sensing and initial contact of the fungus with lignocellulose is an important aspect. Differences and similarities in the responses of fungi to different lignocellulosic substrates can partly be explained with existing understanding of several key regulators and their mode of action, as will be demonstrated for Trichoderma reesei, Neurospora crassa and Aspergillus spp. The regulation of genes encoding Carbohydrate Active enZymes (CAZymes) is influenced by the presence of carbohydrate monomers and short oligosaccharides, as well as the external stimuli of pH and light. We explore several important aspects of the response to lignocellulose that are not related to genes encoding CAZymes, namely the regulation of transporters, accessory proteins and stress responses. The regulation of gene expression is examined from the perspective of mixed cultures and models are presented for the nature of the transcriptional basis for any beneficial effects of such mixed cultures. Various applications in biofuel technology are based on manipulating transcriptional regulation and learning from fungal responses to lignocelluloses. Here we critically access the application of fungal transcriptional responses to industrial saccharification reactions. As part of this chapter, selected regulatory mechanisms are also explored in more detail.

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Regulation of Cellulase and Hemicellulase Gene Expression in Fungi

Cited by 202 publications

References 200 publications

Enzymatic saccharification of pretreated rice straw by cellulases from Aspergillus niger BK01

Enzymatic saccharification of pretreated rice straw by cellulases from Aspergillus niger BK01

Understanding the structure and variation within the genome of the pathogenic ascomycete fungus Leptosphaeria maculans

Transcriptional Regulation and Responses in Filamentous Fungi Exposed to Lignocellulose

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