Anaerobic fungi are among the most active plant‐degrading microbes in nature. Increased insight into the mechanisms and environmental cues that regulate fungal hydrolysis would better inform bioprocessing strategies to depolymerize lignocellulose. Here, we compare the response of three strains of anaerobic fungi (
Biological hydrolysis of microcrystalline cellulose is an uncommon feature in the microbial world, especially among bacteria and archaea growing optimally above 70°C (the so‐called extreme thermophiles). In fact, among this group only certain species in the genus
- NSF-PAR ID:
- 10068544
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- AIChE Journal
- Volume:
- 64
- Issue:
- 12
- ISSN:
- 0001-1541
- Page Range / eLocation ID:
- p. 4218-4228
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Piromyces finnis ,Anaeromyces robustus , andNeocallimastix californiae ) to catabolite regulation by simple carbohydrates. Anaerobic fungi exhibited high enzymatic activity against crystalline cellulose, which was repressed upon incubation with free sugars. Cellulolytic degradation was also inhibited when fungi were exposed to sugars they did not metabolize, suggesting a general mode of catabolite repression. RNA‐Seq experiments in the presence of excess glucose confirmed repression of carbohydrate active enzymes during sugar uptake, and offer a path towards unmasking the function of co‐regulated genes that could be involved in biomass degradation. Overall, these results suggest that sugar‐rich hydrolysates tune the behavior of anaerobic fungi by dampening production of their biomass‐degrading enzymes. © 2018 American Institute of Chemical EngineersAIChE J , 64: 4263–4270, 2018 -
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ABSTRACT Cellulose‐based polymer brushes with variable grafting densities and low dispersity were synthesized by grafting poly(
n ‐butyl acrylate) (PBA) side chains from cellulose‐derived backbones via ATRP. Esterification of commercially available cellulose acetate with 2‐bromoisobutyryl bromide (2‐BiBB) in NMP provided cellulose‐based macroinitiators averaging one initiation site per double glucose unit. ATRP macroinitiators averaging up to 6 initiation sites per repeating double glucose unit were prepared by acylation of microcrystalline cellulose (MCC) in LiCl/DMAc solvent system with 2‐BiBB. A series of linear macroinitiators with narrow MWD were obtained by fractional precipitation process. The content of initiating sites was determined by elemental analysis. (Meth)acrylate side chains were then grafted from the cellulose‐based macroinitiators. The prepared cellulose‐based polymer brushes showed tunable degradation rates dependent on grafting density of the brush, following two different degradation pathways, either cleavage of the main chain or detachment of the side chains. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2019 ,57 , 2426–2435 -
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Abstract Background Future expansion of corn-derived ethanol raises concerns of sustainability and competition with the food industry. Therefore, cellulosic biofuels derived from agricultural waste and dedicated energy crops are necessary. To date, slow and incomplete saccharification as well as high enzyme costs have hindered the economic viability of cellulosic biofuels, and while approaches like simultaneous saccharification and fermentation (SSF) and the use of thermotolerant microorganisms can enhance production, further improvements are needed. Cellulosic emulsions have been shown to enhance saccharification by increasing enzyme contact with cellulose fibers. In this study, we use these emulsions to develop an emulsified SSF (eSSF) process for rapid and efficient cellulosic biofuel production and make a direct three-way comparison of ethanol production between
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