Saccharification of agricultural lignocellulosic feedstocks by endogenous and symbiotic cellulases from the subterranean termites

2021 ◽  
pp. 102265
Author(s):  
Muhammad Afzal ◽  
Nargis Shaheen ◽  
Syed Aizaz Ali Shah ◽  
Attiya Iqbal ◽  
Michael E. Scharf ◽  
...  
Keyword(s):  
Subterranean Termites ◽  
Lignocellulosic Feedstocks

Saccharification of Agricultural Lignocellulosic Feedstocks by Endogenous and Symbiotic Cellulases from the Subterranean Termites

2020 ◽  
Author(s):  
Muhammad Afzala ◽  
Nargis Shaheen ◽  
Syed Aizaz Ali Shah ◽  
attiya iqbal ◽  
Zachery Wolf ◽  
...  
Keyword(s):  
Subterranean Termites ◽  
Lignocellulosic Feedstocks

scholarly journals Further engineering of R. toruloides for the production of terpenes from lignocellulosic biomass

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
James Kirby ◽  
Gina M. Geiselman ◽  
Junko Yaegashi ◽  
Joonhoon Kim ◽  
Xun Zhuang ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Copy Number ◽  
Mevalonate Pathway ◽  
Mevalonate Kinase ◽  
Metabolite Analysis ◽  
Lignocellulosic Hydrolysate ◽  
Microbial Conversion ◽  
Lignocellulosic Hydrolysates ◽  
Lignocellulosic Feedstocks ◽  
Fuels And Chemicals

Abstract Background Mitigation of climate change requires that new routes for the production of fuels and chemicals be as oil-independent as possible. The microbial conversion of lignocellulosic feedstocks into terpene-based biofuels and bioproducts represents one such route. This work builds upon previous demonstrations that the single-celled carotenogenic basidiomycete, Rhodosporidium toruloides, is a promising host for the production of terpenes from lignocellulosic hydrolysates. Results This study focuses on the optimization of production of the monoterpene 1,8-cineole and the sesquiterpene α-bisabolene in R. toruloides. The α-bisabolene titer attained in R. toruloides was found to be proportional to the copy number of the bisabolene synthase (BIS) expression cassette, which in turn influenced the expression level of several native mevalonate pathway genes. The addition of more copies of BIS under a stronger promoter resulted in production of α-bisabolene at 2.2 g/L from lignocellulosic hydrolysate in a 2-L fermenter. Production of 1,8-cineole was found to be limited by availability of the precursor geranylgeranyl pyrophosphate (GPP) and expression of an appropriate GPP synthase increased the monoterpene titer fourfold to 143 mg/L at bench scale. Targeted mevalonate pathway metabolite analysis suggested that 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGR), mevalonate kinase (MK) and phosphomevalonate kinase (PMK) may be pathway bottlenecks are were therefore selected as targets for overexpression. Expression of HMGR, MK, and PMK orthologs and growth in an optimized lignocellulosic hydrolysate medium increased the 1,8-cineole titer an additional tenfold to 1.4 g/L. Expression of the same mevalonate pathway genes did not have as large an impact on α-bisabolene production, although the final titer was higher at 2.6 g/L. Furthermore, mevalonate pathway intermediates accumulated in the mevalonate-engineered strains, suggesting room for further improvement. Conclusions This work brings R. toruloides closer to being able to make industrially relevant quantities of terpene from lignocellulosic biomass.

scholarly journals State-of-the-Art Char Production with a Focus on Bark Feedstocks: Processes, Design, and Applications

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 87
Author(s):  
Ali Umut Şen ◽  
Helena Pereira
Keyword(s):  
State Of The Art ◽  
Lignocellulosic Materials ◽  
Heating Rates ◽  
Production Methods ◽  
Slow Pyrolysis ◽  
Production Studies ◽  
Lignocellulosic Feedstocks ◽  
Thermochemical Method ◽  
Superior Surface ◽  
First Time

In recent years, there has been a surge of interest in char production from lignocellulosic biomass due to the fact of char’s interesting technological properties. Global char production in 2019 reached 53.6 million tons. Barks are among the most important and understudied lignocellulosic feedstocks that have a large potential for exploitation, given bark global production which is estimated to be as high as 400 million cubic meters per year. Chars can be produced from barks; however, in order to obtain the desired char yields and for simulation of the pyrolysis process, it is important to understand the differences between barks and woods and other lignocellulosic materials in addition to selecting a proper thermochemical method for bark-based char production. In this state-of-the-art review, after analyzing the main char production methods, barks were characterized for their chemical composition and compared with other important lignocellulosic materials. Following these steps, previous bark-based char production studies were analyzed, and different barks and process types were evaluated for the first time to guide future char production process designs based on bark feedstock. The dry and wet pyrolysis and gasification results of barks revealed that application of different particle sizes, heating rates, and solid residence times resulted in highly variable char yields between the temperature range of 220 °C and 600 °C. Bark-based char production should be primarily performed via a slow pyrolysis route, considering the superior surface properties of slow pyrolysis chars.

scholarly journals Yield improvements in anaerobic digestion of lignocellulosic feedstocks

2021 ◽  
Vol 288 ◽  
pp. 125447
Author(s):  
Behnam Hashemi ◽  
Shiplu Sarker ◽  
Jacob J. Lamb ◽  
Kristian M. Lien
Keyword(s):  
Anaerobic Digestion ◽  
Lignocellulosic Feedstocks

scholarly journals Color change and termite resistance of fast-growing tropical woods treated with kesambi (Schleichera oleosa) smoke

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Yusuf Sudo Hadi ◽  
Muh Yusram Massijaya ◽  
Dodi Nandika ◽  
Wa Ode Muliastuty Arsyad ◽  
Imam Busyra Abdillah ◽  
...  
Keyword(s):  
Color Change ◽  
Acacia Mangium ◽  
Chemical Compounds ◽  
Subterranean Termite ◽  
Subterranean Termites ◽  
Schleichera Oleosa ◽  
Termite Attack ◽  
Wood Resistance ◽  
Tropical Woods ◽  
Anthocephalus Cadamba

Abstract Smoke treatment can be used to enhance wood resistance to subterranean termite attack. In this study, kesambi (Schleichera oleosa) wood was pyrolyzed to produce charcoal. The smoke produced as a by-product of pyrolysis was used to treat sengon (Falcataria moluccana), jabon (Anthocephalus cadamba), mangium (Acacia mangium), and pine (Pinus merkusii) wood samples for 1, 2, or 3 weeks. Following the smoke treatment, the wood specimens were exposed to subterranean termites (Coptotermes curvignathus Holmgren) according to the Indonesian standard 7207-2014 in a laboratory. The color change caused by smoke treatment was observed, and chemical analysis of smoke was also done. The results showed that chemical compounds of kesambi smoke predominantly consisted of acetic acid, phenol, ketones, amines, and benzene. The color of smoked wood became darker, less yellow, and a little redder, while a longer smoking period produced a darker color which was more resistant to termite attack. Smoke treatment enhanced the resistance of wood to subterranean termite attack, and the resistance levels were not significantly different based on the duration of the smoke treatment.

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