Production of L-lactic acid by Escherichia coli JH12 using rice straw hydrolysate as carbon source

2015 ◽  
pp. 719-722
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Carbon Source ◽  
Rice Straw ◽  
Rice Straw Hydrolysate

scholarly journals In SituBiodiesel Production from Fast-Growing and High Oil ContentChlorella pyrenoidosain Rice Straw Hydrolysate

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Penglin Li ◽  
Xiaoling Miao ◽  
Rongxiu Li ◽  
Jianjiang Zhong
Keyword(s):  
Carbon Source ◽  
Rice Straw ◽  
Biomass Concentration ◽  
Chlorella Pyrenoidosa ◽  
Biodiesel Production ◽  
Microalgae Cultivation ◽  
Rice Straw Hydrolysate ◽  
Alternative Carbon Source ◽  
Methyl Ester Content

Rice straw hydrolysate was used as lignocellulose-based carbon source forChlorella pyrenoidosacultivation and the feasibility ofin situbiodiesel production was investigated. 13.7 g/L sugar was obtained by enzymatic hydrolyzation of rice straw.Chlorella pyrenoidosashowed a rapid growth in the rice straw hydrolysate medium, the maximum biomass concentration of 2.83 g/L was obtained in only 48 hours. The lipid content of the cells reached as high as 56.3%.In situtransesterification was performed for biodiesel production. The optimized condition was 1 g algal powder, 6 mLn-hexane, and 4 mL methanol with 0.5 M sulfuric acid at the temperature of 90°C in 2-hour reaction time, under which over 99% methyl ester content and about 95% biodiesel yield were obtained. The results suggested that the method has great potential in the production of biofuels with lignocellulose as an alternative carbon source for microalgae cultivation.

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

The Effects of adhE Deletion on the Metabolism for D-Lactic Acid Production by the Escherichia coli JH11

2012 ◽  
Vol 476-478 ◽  
pp. 2051-2054 ◽  
Author(s):  
Jin Fang Zhao ◽  
Li Yuan Xu ◽  
Yong Ze Wang ◽  
Jin Hua Wang ◽  
Sheng De Zhou
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Carbon Source ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Mineral Salts ◽  
E Coli ◽  
Recombination System ◽  
Recombinant Technology ◽  
A Minor

Escherichia coli W produces a mixture of organic acids during fermentation in mineral salts medium using glucose as the sole carbon source. Among these products, D-lactate, acetate, succinate, and ethanol are the majors, with formate as a minor. In order to evaluate the effect of adhE mutation on the metabolism for D-lactic acid production by E. coli W, an adhE deletion mutant JH11 was constructed using the RED recombination system and the flipase recognition target （FRT） site-specific recombinant technology. Compared to the parent strain, JH11 produced significantly higher concentration of D-lactate due to the increased NADH availability, with slightly changed acetate (increased), and succinate (decreased), in fermentations using mineral salts medium containing glucose as the carbon source and calcium carbonate as the neutralizer.

scholarly journals Lactic acid production ability of Lactobacillus sp. from four tropical fruits using their by-products as carbon source

Heliyon ◽  
2021 ◽  
Vol 7 (5) ◽  
pp. e07079
Author(s):  
Joel Romial Ngouénam ◽  
Chancel Hector Momo Kenfack ◽  
Edith Marius Foko Kouam ◽  
Pierre Marie Kaktcham ◽  
Rukesh Maharjan ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Carbon Source ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Tropical Fruits ◽  
By Products

scholarly journals Effects of Rice Straw Powder (RSP) Size and Pretreatment on Properties of FDM 3D-Printed RSP/Poly(Lactic Acid) Biocomposites

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3234
Author(s):  
Wangwang Yu ◽  
Lili Dong ◽  
Wen Lei ◽  
Yuhan Zhou ◽  
Yongzhe Pu ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Rice Straw ◽  
Fused Deposition Modeling ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Cost Effective ◽  
Poly Lactic Acid ◽  
Fused Deposition ◽  
Interfacial Compatibility ◽  
3D Printed

To develop a new kind of environment-friendly composite filament for fused deposition modeling (FDM) 3D printing, rice straw powder (RSP)/poly(lactic acid) (PLA) biocomposites were FDM-3D-printed, and the effects of the particle size and pretreatment of RSP on the properties of RSP/PLA biocomposites were investigated. The results indicated that the 120-mesh RSP/PLA biocomposites (named 120#RSP/PLA) showed better performance than RSP/PLA biocomposites prepared with other RSP sizes. Infrared results showed that pretreatment of RSP by different methods was successful, and scanning electron microscopy indicated that composites prepared after pretreatment exhibited good interfacial compatibility due to a preferable binding force between fiber and matrix. When RSP was synergistically pretreated by alkaline and ultrasound, the composite exhibited a high tensile strength, tensile modulus, flexural strength, and flexural modulus of 58.59, 568.68, 90.32, and 3218.12 MPa, respectively, reflecting an increase of 31.19%, 16.48%, 18.75%, and 25.27%, respectively, compared with unmodified 120#RSP/PLA. Pretreatment of RSP also improved the thermal stability and hydrophobic properties, while reducing the water absorption of 120#RSP/PLA. This work is believed to provide highlights of the development of cost-effective biocomposite filaments and improvement of the properties of FDM parts.

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