scholarly journals Polyhydroxyalkanoate production from rice straw hydrolysate obtained by alkaline pretreatment and enzymatic hydrolysis using Bacillus strains isolated from decomposing straw

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Doan Van Thuoc ◽  
Nguyen Thi Chung ◽  
Rajni Hatti-Kaul
Keyword(s):  
Enzymatic Hydrolysis ◽  
Rice Straw ◽  
Nile Blue ◽  
Low Cost ◽  
Alkaline Pretreatment ◽  
Blue Staining ◽  
Rrna Gene ◽  
Rice Straw Hydrolysate ◽  
Different Temperatures ◽  
Pha Production

AbstractRice straw is an important low-cost feedstock for bio-based economy. This report presents a study in which rice straw was used both as a source for isolation of bacteria producing the biodegradable polyester polyhydroxyalkanoate (PHA), as well as the carbon source for the production of the polymer by the isolated bacteria. Of the 100 bacterial isolates, seven were found to be positive for PHA production by Nile blue staining and were identified as Bacillus species by 16S rRNA gene sequence analysis. Three isolates showed 100% sequence identity to B. cereus, one to B. paranthracis, two with 99 and 100% identity to B. anthracis, while one was closely similar to B. thuringiensis. For use in PHA production, rice straw was subjected to mild alkaline pretreatment followed by enzymatic hydrolysis. Comparison of pretreatment by 2% sodium hydroxide, 2% calcium hydroxide and 20% aqueous ammonia, respectively, at different temperatures showed maximum weight loss with NaOH at 80 °C for 5 h, but ammonia for 15 h at 80 °C led to highest lignin removal of 63%. The ammonia-pretreated rice straw also led to highest release of total reducing sugar up to 92% on hydrolysis by a cocktail of cellulases and hemicellulases at 50 °C. Cultivation of the Bacillus isolates on the pretreated rice straw revealed highest PHA content of 59.3 and 46.4%, and PHA concentration of 2.96 and 2.51 g/L by Bacillus cereus VK92 and VK98, respectively.

scholarly journals Utilization of palm oil mill effluent and clindamycin for optimization of polyhydroxy [r] alkanoates production

2019 ◽  
Vol 10 (1) ◽  
pp. 4740-4746
Keyword(s):  
Palm Oil ◽  
Volatile Fatty Acids ◽  
Production Condition ◽  
Nile Blue ◽  
Carbon Sources ◽  
Palm Oil Mill Effluent ◽  
Blue Staining ◽  
Storage Granules ◽  
Pha Production ◽  
Palm Oil Mill

Polyhydroxyalkanoates (PHA) are storage granules of most bacteria which can be used as biodegradable plastics but the production cost of PHA is twice than petrochemical based synthetic polymers because of substrate cost. The use of alternative renewable and cheap carbon sources are the best option, one such is palm oil mill effluent (POME). POME contains carbon source like volatile fatty acids and other organic components which can be utilised by microorganisms to accumulate PHA. The use of subinhibitory concentration of antibiotics like clindamycin may have an influence on PHA accumulation. In this study, 31 organisms were isolated from POME spillage area and subjected to PHA production. Seven organisms were found to accumulate PHA, which was confirmed by Nile blue staining method, the accumulated PHA was extracted and characterized using HPLC. All the organisms were found to produced poly hydroxy butyrate (PHB). Amongst all the seven isolates, two organisms namely Bacillus sp and Pseudomonas aeruginosa were found to accumulate more PHA. Both the organisms were subjected to produce PHA in POME and clindamycin containing media. PHA production condition was optimized using RSM.

scholarly journals Short Communication: Isolation and screening of polyhydroxylalkanoates producing microorganisms from Thailand

2021 ◽  
Vol 22 (11) ◽  
Author(s):  
Nuntaporn Pungsungvorn ◽  
Anussorn Wisetsing
Keyword(s):  
Rice Straw ◽  
18S Rrna ◽  
Short Communication ◽  
Nile Red ◽  
Enterobacter Cloacae ◽  
Klebsiella Pneumonia ◽  
Bacterial Strains ◽  
Yeast Isolate ◽  
Rice Straw Hydrolysate ◽  
Pha Production

Abstract. Pungsungvorn N, Wisetsing A. 2021. Short Communication: Isolation and screening of polyhydroxylalkanoates producing microorganisms from Thailand. Biodiversitas 22: 4963-4967. Polyhydroxylalkanotes (PHAs) are polyesters produced in nature by numerous microorganisms. They are biodegradable and are used in the production of bioplastics. In this study, one hundred twenty samples from different regions of Thailand were collected and screened for polyhydroxylalkanoates (PHAs) producing microorganisms. The samples were screened on YM agar containing 0.5 µg Nile-red/mL (YM-NR). Only one isolate of yeast (Y1) gave a positive result on PHA accumulation. The yeast isolate (Y1) was identified as Candida tropicalis by API 20C AUX kit and 18S rRNA nucleotide comparison. The yeast isolate Y1 produced 2.62% PHA   when grown in synthetic N-limiting medium using rice straw hydrolysate as carbon source. The selected four bacteria (B1, B2, B3 and B4) were identified by BlastN of 16S rRNA as Enterobacter cloacae, Enterobacter carcerogenus, Escherichia coli and Klebsiella pneumonia, respectively. The selected yeast and bacterial strains gave PHA content of 2.62, 2.76, 5.38, 3.66 and 0.44%, respectively, in synthetic N-limiting medium using rice straw hydrolysate. Hence, these microorganisms could be used in PHA production from biomass in the future.

scholarly journals Evaluasi Perlakuan Pendahuluan Menggunakan Kalsium Hidroksida untuk Biokonversi Jerami Padi Menjadi L-Asam Laktat oleh Rhizopus oryzae AT3 (Evaluation of Lime Pretreatment for Bioconversion of Rice Straw to L-Lactic Acid by Rhizopus Oryzae AT3)

2016 ◽  
Vol 36 (03) ◽  
pp. 253
Author(s):  
Dhina Aprilia Nurani Widyahapsari ◽  
Retno Indrati ◽  
Sigit Setyabudi ◽  
Sardjono Sardjono
Keyword(s):  
Lactic Acid ◽  
Solid State ◽  
Enzymatic Hydrolysis ◽  
Rice Straw ◽  
Solid State Fermentation ◽  
Reducing Sugars ◽  
Rhizopus Oryzae ◽  
Crude Enzyme ◽  
Lime Pretreatment ◽  
Rice Straw Hydrolysate

L-lactic acid can be used as a precursor of polylactic acid (PLA). PLA is a biodegradable biomaterial commonly used for biodegradable plastics. Lactic acid can be produced from lignocelluloses materials such as rice straw. Rice straw is composed of cellulose and hemicellulose that can be hydrolyzed to fermentable sugar by cellulolytic and hemicellulolytic enzymes then converted to L-lactic acid by Rhizopus oryzae. As most cellulose and hemicellulose present in lignocellulose biomass are not readily accessible for these enzyme, pretreatment is required to alter the structure of lignocellulose substrates. This research aimed to investigate the effect of lime pretreatment on rice straw bioconversion to L-lactic acid by Rhizopus oryzae AT3. Rice straw was pretreated with lime (Ca(OH)2) at 85 °C for 16 hours. Unpretreated and pretreated rice straw were hydrolyzed using crude enzyme that produced by Trichoderma reesei Pk1J2. Enzyme production was carried out by solid state fermentation using rice straw and rice brand as substrate. Enzymatic hydrolysis was carried out in flasks. Each flask was added with unpretreated or pretreated rice straw, buffer citrate solution and crude enzyme then hydrolyzed for 0-96 hours. Hydrolysate was fermented by Rhizopus oryzae AT3 for 0-6 days by using adsorbed carrier solid-state fermentation method with polyurethane foam as inert support material. Lime pretreatment at 85 °C for 16 hour led to significant solubilisation of lignin and hemicellulose. It involved lignocellulose structure modified that enhance enzymatic hydrolysis and resulted higher reducing sugars than unpretreated rice straw. The high reducing sugars was not related to high lactic acid yields. Fermentation of pretreated rice straw hydrolysate by Rhizopus oryzae AT3 did not only produce L-lactic acid but also other compound. On the other hand, fermentation of unpretreated rice straw hydrolysate only produced L-lactic acid. ABSTRAKPolimerisasi asam laktat menjadi polylactic acid untuk menghasilkan biodegradable plastic membutuhkan asam laktat dengan isomer spesifik. Rhizopus oryzae adalah mikroorganisme yang spesifik menghasilkan L-asam laktat. Selain itu Rhizopus oryzae dapat menggunakan limbah pertanian seperti jerami padi sebagai substrat. Komponen utama jerami padi merupakan lignoselulosa yang dapat dihidrolisa secara enzimatis menjadi komponen gula sederhana penyusunnya dan selanjutnya dapat dikonversi menjadi L-asam laktat oleh Rhizopus oryzae. Namun struktur lignoselulosa sangat kompak dan rapat, sulit untuk dihidrolisa secara enzimatis sehingga diperlukan adanya perlakuan pendahuluan untuk merombak struktur lignoselulosa agar mudah dihidrolisa. Penelitian ini bertujuan untuk mengetahui pengaruh perlakuan pendahuluan menggunakan kalsium hidroksida (Ca(OH)2) terhadap biokonversi jerami padi menjadi L-asam laktat oleh Rhizopus oryzae AT3. Perlakuan pendahuluan pada jerami padi dilakukan menggunakan (Ca(OH)2) disertai pemanasan suhu 85 °C selama 16 jam. Jerami padi dengan dan tanpa perlakuan pendahuluan dihidrolisa secara enzimatis menggunakan crude enzyme yang diproduksi oleh Trichoderma reesei Pk1J2. Produksi crude enzyme dilakukan dengan fermentasi substrat padat dengan campuran jerami padi dan dedak sebagai substrat. Hidrolisat jerami padi dengan dan tanpa perlakuan pendahuluan selanjutnya difermentasi oleh Rhizopus oryzae AT3 menggunakan metode adsorbed carrier solid state fermentation dengan polyurethane foam (PUF) sebagai bahan pendukung. Perlakuan pendahuluan menggunakan Ca(OH2) disertai pemanasan suhu 85 °C selama 16 jam dapat merubah komposisi lignoselulosa jerami padi yaitu dengan melarutkan lignin dan hemiselulosa. Perubahan komposisi lignoselulosa memudahkan kerja crude enzyme dalam menghidrolisa jerami padi sehingga menghasilkan gula reduksi lebih tinggi dibandingkan jerami padi tanpa perlakuan pendahuluan. Tingginya gula reduksi tidak serta merta meningkatkan yield L-asam laktat yang dihasilkan. Fermentasi hidrolisat jerami padi dengan perlakuan pendahuluan oleh Rhizopus oryzae AT3 menghasilkan yield L-asam laktat lebih rendah dibandingkan hidrolisat jerami padi tanpa perlakuan pendahuluan. Namun pada jerami padi dengan perlakuan pendahuluan dihasilkan senyawa lain selain asam laktat.Kata Kunci: Adsorbed carrier solid state fermentation; L-asam laktat; perlakuan pendahuluan; Rhizopus oryzae AT3; jerami padi

scholarly journals Alkaline pretreatment and enzymatic hydrolysis of corn stover for bioethanol production

2021 ◽  
Vol 10 (11) ◽  
pp. e149101118914
Author(s):  
Letícia Renata Bohn ◽  
Aline Perin Dresch ◽  
Matheus Cavali ◽  
Ana Carolina Giacomelli Vargas ◽  
Jaíne Flach Führ ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Corn Stover ◽  
Raw Materials ◽  
Low Cost ◽  
Alkaline Pretreatment ◽  
Bioethanol Production ◽  
Lignocellulosic Residues ◽  
Wild Yeast ◽  
Hydrolysis Of ◽  
Cellic Ctec2

The demand for ethanol in Brazil is growing. However, although the country is one of the largest producers of this fuel, it is still necessary to diversify the production matrix. In that regard, studies with different raw materials are needed, mainly the use of low cost and high available wastes such as lignocellulosic residues from agriculture. Therefore, this study aimed to analyze the bioethanol production from corn stover. An alkaline pretreatment (CaO) was carried out, followed by enzymatic hydrolysis (Cellic Ctec2 and Cellic Htec2) to obtain fermentable sugars. The best experimental condition for the pretreatment and hydrolysis steps resulted in a solution with 0.31 gsugar∙gbiomass-1. Then, the fermentation was performed by the industrial strain of Saccharomyces cerevisiae (PE-2) and by the wild yeast strain Wickerhamomyces sp. (UFFS-CE-3.1.2). The yield obtained was 0.38 gethanol∙gdry biomass-1 was, demonstrating the potential of this process for bioethanol production.

scholarly journals Metabolic pathways inferred from a bacterial marker gene illuminate ecological changes across South Pacific frontal boundaries

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eric J. Raes ◽  
Kristen Karsh ◽  
Swan L. S. Sow ◽  
Martin Ostrowski ◽  
Mark V. Brown ◽  
...  
Keyword(s):  
16S Rrna ◽  
Metabolic Pathways ◽  
Low Cost ◽  
Marker Gene ◽  
South Pacific ◽  
Rrna Gene ◽  
South Pacific Ocean ◽  
Bacterial Marker ◽  
Gene 16S Rrna ◽  
Gene Data

AbstractGlobal oceanographic monitoring initiatives originally measured abiotic essential ocean variables but are currently incorporating biological and metagenomic sampling programs. There is, however, a large knowledge gap on how to infer bacterial functions, the information sought by biogeochemists, ecologists, and modelers, from the bacterial taxonomic information (produced by bacterial marker gene surveys). Here, we provide a correlative understanding of how a bacterial marker gene (16S rRNA) can be used to infer latitudinal trends for metabolic pathways in global monitoring campaigns. From a transect spanning 7000 km in the South Pacific Ocean we infer ten metabolic pathways from 16S rRNA gene sequences and 11 corresponding metagenome samples, which relate to metabolic processes of primary productivity, temperature-regulated thermodynamic effects, coping strategies for nutrient limitation, energy metabolism, and organic matter degradation. This study demonstrates that low-cost, high-throughput bacterial marker gene data, can be used to infer shifts in the metabolic strategies at the community scale.

scholarly journals Generation of highly amenable cellulose-Iβ via selective delignification of rice straw using a reusable cyclic ether-assisted deep eutectic solvent system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chiranjeevi Thulluri ◽  
Ravi Balasubramaniam ◽  
Harshad Ravindra Velankar
Keyword(s):  
Enzymatic Hydrolysis ◽  
Rice Straw ◽  
Deep Eutectic Solvent ◽  
Solvent System ◽  
Cyclic Ether ◽  
Cellulolytic Enzymes ◽  
Ammonium Bromide ◽  
Selective Delignification ◽  
Cellulose Iβ ◽  
Hydrolysis Of

AbstractCellulolytic enzymes can readily access the cellulosic component of lignocellulosic biomass after the removal of lignin during biomass pretreatment. The enzymatic hydrolysis of cellulose is necessary for generating monomeric sugars, which are then fermented into ethanol. In our study, a combination of a deep eutectic (DE) mixture (of 2-aminoethanol and tetra-n-butyl ammonium bromide) and a cyclic ether (tetrahydrofuran) was used for selective delignification of rice straw (RS) under mild conditions (100 °C). Pretreatment with DE-THF solvent system caused ~ 46% delignification whereas cellulose (~ 91%) and hemicellulose (~ 67%) recoveries remained higher. The new solvent system could be reused upto 10 subsequent cycles with the same effectivity. Interestingly, the DE-THF pretreated cellulose showed remarkable enzymatic hydrolysability, despite an increase in its crystallinity to 72.3%. Contrary to conventional pretreatments, we report for the first time that the enzymatic hydrolysis of pretreated cellulose is enhanced by the removal of lignin during DE-THF pretreatment, notwithstanding an increase in its crystallinity. The current study paves way for the development of newer strategies for biomass depolymerization with DES based solvents.

scholarly journals Meta-Apo improves accuracy of 16S-amplicon-based prediction of microbiome function

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gongchao Jing ◽  
Yufeng Zhang ◽  
Wenzhi Cui ◽  
Lu Liu ◽  
Jian Xu ◽  
...  
Keyword(s):  
16S Rrna ◽  
Large Scale ◽  
Low Cost ◽  
Human Microbiome ◽  
Amplicon Sequencing ◽  
Training Sample ◽  
Rrna Gene ◽  
16S Amplicon Sequencing ◽  
Cross Platform ◽  
Functional Profiles

Abstract Background Due to their much lower costs in experiment and computation than metagenomic whole-genome sequencing (WGS), 16S rRNA gene amplicons have been widely used for predicting the functional profiles of microbiome, via software tools such as PICRUSt 2. However, due to the potential PCR bias and gene profile variation among phylogenetically related genomes, functional profiles predicted from 16S amplicons may deviate from WGS-derived ones, resulting in misleading results. Results Here we present Meta-Apo, which greatly reduces or even eliminates such deviation, thus deduces much more consistent diversity patterns between the two approaches. Tests of Meta-Apo on > 5000 16S-rRNA amplicon human microbiome samples from 4 body sites showed the deviation between the two strategies is significantly reduced by using only 15 WGS-amplicon training sample pairs. Moreover, Meta-Apo enables cross-platform functional comparison between WGS and amplicon samples, thus greatly improve 16S-based microbiome diagnosis, e.g. accuracy of gingivitis diagnosis via 16S-derived functional profiles was elevated from 65 to 95% by WGS-based classification. Therefore, with the low cost of 16S-amplicon sequencing, Meta-Apo can produce a reliable, high-resolution view of microbiome function equivalent to that offered by shotgun WGS. Conclusions This suggests that large-scale, function-oriented microbiome sequencing projects can probably benefit from the lower cost of 16S-amplicon strategy, without sacrificing the precision in functional reconstruction that otherwise requires WGS. An optimized C++ implementation of Meta-Apo is available on GitHub (https://github.com/qibebt-bioinfo/meta-apo) under a GNU GPL license. It takes the functional profiles of a few paired WGS:16S-amplicon samples as training, and outputs the calibrated functional profiles for the much larger number of 16S-amplicon samples.

Enzymatic Hydrolysis of Ammonia-Treated Rice Straw

2003 ◽  
Vol 105 (1-3) ◽  
pp. 155-164 ◽  
Author(s):  
Betzabé Sulbarán-De-Ferrer ◽  
Marielena Aristiguieta ◽  
Bruce E. Dale ◽  
Alexis Ferrer ◽  
Graciela Ojeda-De-Rodriguez
Keyword(s):  
Enzymatic Hydrolysis ◽  
Rice Straw ◽  
Hydrolysis Of
Sign in / Sign up

Export Citation Format

Share Document