Title: Identification and manipulation of Neurospora crassa genes involved in sensitivity to furfural

Abstract

Background: Biofuels derived from lignocellulosic biomass are a viable alternative to fossil fuels required for transportation. Following plant biomass pretreatment, the furan derivative furfural is present at concentrations which are inhibitory to yeasts. Detoxification of furfural is thus important for efficient fermentation. Here, we searched for new genetic attributes in the fungus Neurospora crassa that may be linked to furfural tolerance. The fact that furfural is involved in the natural process of sexual spore germination of N. crassa and that this fungus is highly amenable to genetic manipulations makes it a rational candidate for this study. Results: Both hypothesis-based and unbiased (random promotor mutagenesis) approaches were performed to identify N. crassa genes associated with the response to furfural. Changes in the transcriptional profile following exposure to furfural revealed that the affected processes were, overall, similar to those observed in Saccharomyces cerevisiae. N. crassa was more tolerant (by ~ 30%) to furfural when carboxymethyl cellulose was the main carbon source as opposed to sucrose, indicative of a link between carbohydrate metabolism and furfural tolerance. We also observed increased tolerance in a Δ cre-1 mutant (CRE-1 is a key transcription factor that regulates the ability of fungi to utilize non-preferred carbon sources).more » In addition, analysis of aldehyde dehydrogenase mutants showed that ahd-2 (NCU00378) was involved in tolerance to furfural as well as the predicted membrane transporter NCU05580 ( flr-1), a homolog of FLR1 in S. cerevisiae. Further to the rational screening, an unbiased approach revealed additional genes whose inactivation conferred increased tolerance to furfural: (i) NCU02488, which affected the abundance of the non-anchored cell wall protein NCW-1 (NCU05137), and (ii) the zinc finger protein NCU01407. Conclusions:We identified attributes in N. crassa associated with tolerance or degradation of furfural, using complementary research approaches. The manipulation of the genes involved in furan sensitivity can provide a means for improving the production of biofuel producing strains. Similar research approaches can be utilized in N. crassa and other filamentous fungi to identify additional attributes relevant to other furans or toxic chemicals.« less

Authors:

Feldman, Daria ^[1]; Kowbel, David J. ^[2]; Cohen, Adi ^[1]; Glass, N. Louise ^[3]; Hadar, Yitzhak ^[1]; Yarden, Oded  ^[1]

• Search DOE PAGES for author "Yarden, Oded"
• Search DOE PAGES for ORCID "0000-0002-4722-535X"
• Search orcid.org for ORCID "0000-0002-4722-535X"

---

+ Show Author Affiliations

1. Hebrew Univ. of Jerusalem, Rehovot (Israel). Dept. of Plant Pathology and Microbiology
2. Univ. of California, Berkeley, CA (United States). Dept. of Plant and Microbial Biology
3. Univ. of California, Berkeley, CA (United States). Dept. of Plant and Microbial Biology; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Genomics and Systems Biology Division

Publication Date:

2019-09-04

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1571949

Grant/Contract Number:  

AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Biotechnology for Biofuels

Additional Journal Information:

Journal Volume: 12; Journal Issue: 1; Journal ID: ISSN 1754-6834

Publisher:

BioMed Central

Country of Publication:

United States

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES