Optimization of Pre-treatment Using RSM on Wheat Straw and Production of Lactic Acid Using Thermotolerant, Inhibitor Tolerant and Xylose Utilizing Bacillus Sonorenesis Strain DGS15

Author(s):  
Simarpreet Kaur Chawla ◽  
Dinesh Goyal

Abstract Thermotolerant lactic acid producing bacteria, isolated from red soil of brick kiln was identified by 16S rRNA sequencing as Bacillus sonorenesis , which showed remarkable capability to ferment sugars of lignocellulosic biomass after pre-treatment, yielding 0.97 g/g lactic acid with overall productivity of 0.38 g L -1/ h. RSM was employed to optimize the sulphuric acid pre-treatment combined with dilute NaOH and hot water pre-treatment. Pretreated wheat straw biomass had 40.4% cellulose, 18.4% hemicellulose, 12.4% lignin and 28.2 g L -1 reducing sugar, while native wheat straw biomass had 36% cellulose, 25% hemicellulose, 20% total lignin, and 0.94 g L -1 reducing sugar. Scanning electron microscopy (SEM) revealed that the ordered and compact structure of wheat straw was destroyed upon pre-treatment. X-ray diffractogram (XRD) revealed 9.71% increase in crystallinity index ( CrI ) in pretreated biomass. FTIR spectrogram showed removal of lignin due to reduction of peak at 1640 cm -1 in pretreated biomass. Bacillus sonorenesis DGS15 is inhibitor tolerant (furfural (1.2 g L -1 ) and HMF (2.4 g L -1 )). Furfural was consumed after 72 h of fermentation and HMF got accumulated with 3.75-fold increase in concentration in the fermentation broth. In terms of final concentration, yield, and fermentation duration, this is the best performance of DGS15 for lactic acid production utilizing xylose, glucose as the carbon source. All of these findings showed that the thermotolerant Bacillus sonorenesis strain DGS15 is a novel, attractive candidate for producing lactic acid from lignocellulosic biomass.

2020 ◽  
Vol 21 (5) ◽  
Author(s):  
WHINY HARDIYATI ERLIANA ◽  
Tri Widjaja ◽  
ALI ALTWAY ◽  
LILY PUDJIASTUTI

Abstract. Erliana WH, Widjaja T, Altway A, Pudjiastuti L. 2020. Synthesis of lactic acid from sugar palm trunk waste (Arenga pinnata): Hydrolysis and fermentation studies. Biodiversitas 21: 2281-2288. The increasing problems of global energy and the environment are the main reasons for developing products with new techniques through green methods. Sugar palm trunk waste (SPTW) has potential as agricultural waste because of its abundant availability, but it is not used optimally. This study was aimed to determine the effect of various microorganisms on increasing lactic acid production by controlling pH and temperature conditions in the fermentation process. SPTW contains 43.88% cellulose, 7.24% hemicellulose, and 33.24% lignin. The lignin content in SPTW can inhibit reducing sugar formation; the pretreatment process should remove this content. In the study, the pretreatment process was conducted using acid-organosolv. In the acid pretreatment, 0.2 M H2SO4 was added at 120oC for 40 minutes; organosolv pretreatment using 30% ethanol (v/v) at 107oC for 33 minutes was able to increase cellulose content by 56.33% and decrease lignin content by 27.09%. The pretreatment was followed by an enzymatic hydrolysis process with a combination of commercial cellulase enzymes from Aspergillus niger (AN) and Trichoderma reesei (TR), with variations of 0:1, 1:0, 1:1, 1:2 and 2:1. The best reducing sugar concentration was obtained with an AN: TR ratio of 1:2 to form reducing sugar from cellulose. Subsequently, lactic acid fermentation was carried out using lactic acid bacteria at 37oC and pH 6 incubated for 48 hours. The highest lactic acid concentration (33.292 g/L) was obtained using a mixed culture of Lactobacillus rhamnosus and Lactobacillus brevis to convert reducing sugar become lactic acid.


2018 ◽  
Vol 36 (No. 2) ◽  
pp. 146-153 ◽  
Author(s):  
Gharwalová Lucia ◽  
Paulová Leona ◽  
Patáková Petra ◽  
Branská Barbora ◽  
Melzoch Karel

Biotechnological production of lactic acid has experienced a boom that is hindered only by the lack of low-cost, abundant material that might be used as a substrate for lactic acid bacteria. Such material should contain not only carbon but also complex nitrogen sources, amino acids and vitamins necessary for the balanced growth of the bacteria. Here, for the first time, a combination of hydrolysates of wheat straw and chicken feathers was used as a complete waste cultivation medium for lactic acid production. It was shown to be a promising substrate for lactic acid production, reducing the medium price by 73% compared with MRS broth, providing more than 98% lactic acid yield and high productivity (2.28 ± 0.68 g/l/h) in a fed-batch process using Lactobacillus reuterii LHR14.


2019 ◽  
Vol 3 (2) ◽  
pp. 43 ◽  
Author(s):  
Nuttakul Mungma ◽  
Marlene Kienberger ◽  
Matthäus Siebenhofer

The present work develops the basics for the isolation of lactic acid, acetic acid and formic acid from a single as well as a mixed feed stream, as is present, for example, in fermentation broth for lactic acid production. Modelling of the phase equilibria data is performed using the law of mass action and shows that the acids are extracted according to their pka value, where formic acid is preferably extracted in comparison to lactic and acetic acid. Back-extraction was performed by 1 M NaHCO3 solution and shows the same tendency regarding the pka value. Based on lactic acid, the solvent phase composition, consisting of tri-n-octylamine/1-octanol/n-undecane, was optimized in terms of the distribution coefficient. The data clearly indicate that, compared to physical extraction, mass transfer can be massively enhanced by reactive extraction. With increasing tri-n-octylamine and 1-octanol concentration, the equilibrium constant increases. However, even when mass transfer increases, tri-n-octylamine concentrations above 40 wt%, lead to third phase formation, which needs to be prevented for technical application. The presented data are the basis for the transfer to liquid membrane permeation, which enables the handling of emulsion tending systems.


2008 ◽  
Vol 78 (5) ◽  
pp. 751-758 ◽  
Author(s):  
Ronald H. W. Maas ◽  
Robert R. Bakker ◽  
Mickel L. A. Jansen ◽  
Diana Visser ◽  
Ed de Jong ◽  
...  

Author(s):  
Carmen Leane NICOLESCU ◽  
Lavinia Claudia BURULEANU

Using Lactobacillus acidophilus stains is a challenge in producing lactic acid fermented vegetable and fruit juices. There were analysed the correlation between the most important physico-chemical parameters of the substrate and the bacterial biomass accumulation in two vegetable and fruit juices. The data were collected during a 48 hour lactic acid fermentation using usually chemical and microbiological methods. There was analysed the correlation between the reducing sugar content and the lactic acid production, the correlation between the pH and lactic acid production, the correlation between the reducing sugar of the substrate and the microbial biomass accumulation and also between the lactic acid production and biomass accumulation. These correlations were analysed using simple regression on scatter plots. They were best fitted by the polynomial equation where the highest R2 were calculated. The two last correlations had large differences between the two experimental batches so that regression is not satisfactory to describe them. If all parameters were considered using the multiple regression, the correlation had a medium value because the cell multiplication of the bacteria Lactobacillus acidophilus in vegetable and fruit juices is influenced by many other environmental parameters. These had a large influence because juices are not the natural medium for this kind of lactic acid bacteria.


2018 ◽  
Vol 14 (3) ◽  
pp. 353-359 ◽  
Author(s):  
Zulfah Zulkifli ◽  
Nazaitulshila Rasit ◽  
Noor Azrimi Umor ◽  
Shahrul Ismail

Lignocellulosic material consists of lignin, cellulose and hemicellulose. Converting lignocellulosic biomass such as cow manure (CM) into value-added products provides a potential alternative. Hydrolysis of cellulose and hemicellulose is a limiting step during Anaerobic Digestion (AD) of lignocellulosic biomass. Lignin in lignocellulosic biomass is the barrier for hydrolysis, thus limits the biogas production. In this study, the effect of A.Fumigatus SK1 and Trichoderma sp. on enzymatic pre-treatment of CM was investigated with respect to the biogas production. Three set of anaerobic digestion assays were carried out, with a working volume of 500 mL at 35 ± 2°C and 120 rpm. The first set of fermentation contained untreated CM. The second set of fermentation involved addition of A.Fumigatus SK1, and the last set contained Trichoderma sp. Several analysis were conducted to determine the biomethane potential (BMP), anaerobic biodegradability, reducing sugars concentration and lignin removal of CM before and after pre-treatment. Result showed that, among both evaluated pre-treatment methods, CM treated with Trichoderma sp. gave the highest methane potential with 0.023 LCH4-STP g VS-1 compared to CM treated with A.Fumigatus SK1(0.011 LCH4-STP g VS-1). A good correlation have been found in this study between lignin removal and reducing sugar produced where, the total lignin removal after treated with Trichoderma sp. was 60% followed by 43% after treated with A.Fumigatus SK1.The reducing sugar produced after pre-treated with Trichoderma sp. and A.Fumigatus SK1 was about 9.59 and 4.91 μmol glucose, respectively. These results collectively suggested that CM treated with Trichoderma sp. could be a better pre-treatment method for the higher methane production in anaerobic mono-digestion process.


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