Alkali pretreatment at ambient temperature: A promising method to enhance biomethanation of rice straw

Shetty, Deepa; Kshirsagar, Pranav R.; Tapadia-Maheshwari, Sneha; Lanjekar, Vikram; Singh, Sanjay K.; Dhakephalkar, Prashant K.

doi:10.1016/j.biortech.2016.12.003

Cited by 110 publications

(36 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A study on the alkaline pretreatment of rice straw for biomethane production reported that 1% NaOH at room temperature for 3 h significantly reduces the hemicellulose and lignin contents while the cellulose content remains unaltered. This led to an increase of methane yield by more than 34% compared to untreated rice straw (Shetty et al, 2017). Likewise, Talha et al (2016) optimized the conditions of alkaline pretreatment of sugarcane bagasse and filter mud to enhance biomethanation.…”

Section: Alkali Pretreatmentmentioning

confidence: 99%

Recent Trends in the Pretreatment of Lignocellulosic Biomass for Value-Added Products

et al. 2018

View full text Add to dashboard Cite

Lignocellulosic biomass (LCB) is the most abundantly available bioresource amounting to about a global yield of up to 1. 3 billion tons per year. The hydrolysis of LCB results in the release of various reducing sugars which are highly valued in the production of biofuels such as bioethanol and biogas, various organic acids, phenols, and aldehydes. The majority of LCB is composed of biological polymers such as cellulose, hemicellulose, and lignin, which are strongly associated with each other by covalent and hydrogen bonds thus forming a highly recalcitrant structure. The presence of lignin renders the bio-polymeric structure highly resistant to solubilization thereby inhibiting the hydrolysis of cellulose and hemicellulose which presents a significant challenge for the isolation of the respective bio-polymeric components. This has led to extensive research in the development of various pretreatment techniques utilizing various physical, chemical, physicochemical, and biological approaches which are specifically tailored toward the source biomaterial and its application. The objective of this review is to discuss the various pretreatment strategies currently in use and provide an overview of their utilization for the isolation of high-value bio-polymeric components. The article further discusses the advantages and disadvantages of the various pretreatment methodologies as well as addresses the role of various key factors that are likely to have a significant impact on the pretreatment and digestibility of LCB.

show abstract

Section: Alkali Pretreatmentmentioning

confidence: 99%

Recent Trends in the Pretreatment of Lignocellulosic Biomass for Value-Added Products

et al. 2018

View full text Add to dashboard Cite

show abstract

“…strains were analyzed for the presence of these enzyme activities as well as the maximum expression and activity conditions. A secreted enzyme from the culture media of each strain was collected daily and tested for the two enzyme activities at a variety of temperatures (30-70 C) and pH (3)(4)(5)(6)(7). Table 2 shows the highest activity achieved for the expression and activity condition of each of the two enzymes.…”

Section: Isolation and Characterization Of Lignin-degrading Bacterialmentioning

confidence: 99%

Biological pretreatment of rice straw by ligninolytic Bacillus sp. strains for enhancing biogas production

Shah

Lee

Orts

et al. 2018

Env Prog and Sustain Energy

View full text Add to dashboard Cite

Fermenting agricultural biomass, such as rice straw (RS), to methane is a promising solution to an ongoing waste problem. However, the biomass must first be pretreated to break down lignin thereby increasing accessibility of the substrate to fermentative organisms. Biological pretreatment by microorganisms represents a potentially economical strategy to prepare the biomass for fermentation. We isolated seven candidate ligninolytic Bacillus sp. strains based on their robustness for lignin degradation. The production of the ligninolytic enzymes from these strains was characterized and optimized. The bacterial strains were tested for their ability to pretreat RS and increase the yield of biomethane fermentation. It was determined that using mixed combinations of bacterial cultures was more effective than using individual strains. Overall, the study demonstrates the potential of using these Bacillus sp. strains as robust biocatalysts for processing lignocellulosic waste biomass. Significance: Newly isolated Bacillus sp. strains demonstrated an efficient degradation of lignin, Azure B dye, fast hydrolysis of rice straw, and improved biogas yields. This research suggests that, Bacillus sp. strains could be a source of novel enzymes, and an ideal candidate in bioprocessing of complex substrates”. © 2018 American Institute of Chemical Engineers Environ Prog, 38:e13036, 2019

show abstract

“…The simulated flux values were then obtained from the developed equations with coefficient of determination ( R 2 ) to assess model suitability ( R 2 > 0.7). In many controlled process experiments, parameter optimization for microbial, chemical, and physical parameters an R 2 values >0.75 is considered significant (e.g., Shetty et al, ). In this experiment where multiple unknown and unidentified geobiological parameter might be involved an additional leniency of 5% was applied on the parameterization process, thus considering R 2 > 0.7 as significant fitness of the model.…”

Section: Methodsmentioning

confidence: 99%

Implications of Microbial Thiosulfate Utilization in Red Clay Sediments of the Central Indian Basin: The Martian Analogy

Singh

Kshirsagar

Das

et al. 2019

Geochem Geophys Geosyst

Self Cite

View full text Add to dashboard Cite

Microbial thiosulfate utilization and S-disproportionation could be important mechanisms of sulfate-formations on Earth and Mars. Sulfates on Mars date back to late-Noachian to Hesperian period. In contrast, the large sulfur/sulfate formations on Earth evolved under different chronological sequences. The S-cycle was provoked intermittently, permitting multiple appearances of the S-oxidizers on an evolutionary timescale. Hydrothermally altered deep-oceanic red clay sediments of the Central Indian Basin were examined as potential analogue for sulfur (S) oxidation on Mars. The basin sediments supported an active microbial S-metabolism that exhibited S-disproportionation coupled to microbial carbon-fixation through intermediate processes like thiosulfate utilization. Sulfur-oxidizers/thiotrophic denitrifiers were isolated in large numbers at circum-neutral pH, from these cold and dark abyssal Fe-oxide dominated organic-C starved clay. Experimental simulations under psychrophilic and thermo-tolerant conditions revealed the coexistence of an anaerobic, thermal component under the predominantly oxic, circum-neutral seafloor conditions. Multiple causative factors like hydrothermal seafloor circulation, in situ volcanism, and fracture zone reactivation could drive the widespread S-cycle activity in the Central Indian Basin, albeit at a low scale. It is postulated that these conditions are analogous to Great Oxidation Event situations on Earth, when S-oxidizers evolved and flourished. Experimental studies on microbial thiosulfate flux are few in spite of intense scientific interest in microbial S-disproportionation. To the best of our knowledge, this is a new report on regression model development for microbial thiosulfate flux. These clay-systems and their component microbes could serve as analogue to the ancient well-hydrated Noachian Mars and throw light on planetary hydration and desiccation mechanisms.The Central Indian Basin (CIB) red clays are Fe-oxide dominated, well supplied by oxygenated seawater, usually organic-C-and calcite-depleted environment. The predominantly circum-neutral pH environment often shows sharp pH gradients from 5 to 10. Thus, red clay sediments of CIB were examined for their ability to oxidize/utilize/disproportionate thiosulfate in a Fe-dominant setting. Examining thiosulfate utilization in red clay sediments could provide a glimpse of the hydration-desiccation cycles on Earth and Mars, through mechanisms involving sulfide-sulfate-oxide mineral transitions.

show abstract

Alkali pretreatment at ambient temperature: A promising method to enhance biomethanation of rice straw

Cited by 110 publications

References 28 publications

Recent Trends in the Pretreatment of Lignocellulosic Biomass for Value-Added Products

Recent Trends in the Pretreatment of Lignocellulosic Biomass for Value-Added Products

Biological pretreatment of rice straw by ligninolytic Bacillus sp. strains for enhancing biogas production

Implications of Microbial Thiosulfate Utilization in Red Clay Sediments of the Central Indian Basin: The Martian Analogy

Contact Info

Product

Resources

About