Consolidated bioprocessing of cassava starch into microbial lipid for biodiesel production by the amylolytic yeast Lipomyces starkeyi

2022 ◽  
Vol 177 ◽  
pp. 114534
Author(s):  
Junlu Zhang ◽  
Yanan Wang ◽  
Qingling Gou ◽  
Wei Zhou ◽  
Yantao Liu ◽  
...  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Morakot Krajang ◽  
Kwanruthai Malairuang ◽  
Jatuporn Sukna ◽  
Krongchan Rattanapradit ◽  
Saethawat Chamsart

Abstract Background A single-step ethanol production is the combination of raw cassava starch hydrolysis and fermentation. For the development of raw starch consolidated bioprocessing technologies, this research was to investigate the optimum conditions and technical procedures for the production of ethanol from raw cassava starch in a single step. It successfully resulted in high yields and productivities of all the experiments from the laboratory, the pilot, through the industrial scales. Yields of ethanol concentration are comparable with those in the commercial industries that use molasses and hydrolyzed starch as the raw materials. Results Before single-step ethanol production, studies of raw cassava starch hydrolysis by a granular starch hydrolyzing enzyme, StargenTM002, were carefully conducted. It successfully converted 80.19% (w/v) of raw cassava starch to glucose at a concentration of 176.41 g/L with a productivity at 2.45 g/L/h when it was pretreated at 60 °C for 1 h with 0.10% (v/w dry starch basis) of Distillase ASP before hydrolysis. The single-step ethanol production at 34 °C in a 5-L fermenter showed that Saccharomyces cerevisiae (Fali, active dry yeast) produced the maximum ethanol concentration, pmax at 81.86 g/L (10.37% v/v) with a yield coefficient, Yp/s of 0.43 g/g, a productivity or production rate, rp at 1.14 g/L/h and an efficiency, Ef of 75.29%. Scale-up experiments of the single-step ethanol production using this method, from the 5-L fermenter to the 200-L fermenter and further to the 3000-L industrial fermenter were successfully achieved with essentially good results. The values of pmax,Yp/s, rp, and Ef of the 200-L scale were at 80.85 g/L (10.25% v/v), 0.42 g/g, 1.12 g/L/h and 74.40%, respectively, and those of the 3000-L scale were at 70.74 g/L (8.97% v/v), 0.38 g/g, 0.98 g/L/h and 67.56%, respectively. Because of using raw starch, major by-products, i.e., glycerol, lactic acid, and acetic acid of all three scales were very low, in ranges of 0.940–1.140, 0.046–0.052, 0.000–0.059 (% w/v), respectively, where are less than those values in the industries. Conclusion The single-step ethanol production using the combination of raw cassava starch hydrolysis and fermentation of three fermentation scales in this study is practicable and feasible for the scale-up of industrial production of ethanol from raw starch.


2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Francesca Martani ◽  
Letizia Maestroni ◽  
Mattia Torchio ◽  
Diletta Ami ◽  
Antonino Natalello ◽  
...  

Abstract Background Lipids from oleaginous yeasts emerged as a sustainable alternative to vegetable oils and animal fat to produce biodiesel, the biodegradable and environmentally friendly counterpart of petro-diesel fuel. To develop economically viable microbial processes, the use of residual feedstocks as growth and production substrates is required. Results In this work we investigated sugar beet pulp (SBP) and molasses, the main residues of sugar beet processing, as sustainable substrates for the growth and lipid accumulation by the oleaginous yeast Lipomyces starkeyi. We observed that in hydrolysed SBP the yeast cultures reached a limited biomass, cellular lipid content, lipid production and yield (2.5 g/L, 19.2%, 0.5 g/L and 0.08 g/g, respectively). To increase the initial sugar availability, cells were grown in SBP blended with molasses. Under batch cultivation, the cellular lipid content was more than doubled (47.2%) in the presence of 6% molasses. Under pulsed-feeding cultivation, final biomass, cellular lipid content, lipid production and lipid yield were further improved, reaching respectively 20.5 g/L, 49.2%, 9.7 g/L and 0.178 g/g. Finally, we observed that SBP can be used instead of ammonium sulphate to fulfil yeasts nitrogen requirement in molasses-based media for microbial oil production. Conclusions This study demonstrates for the first time that SBP and molasses can be blended to create a feedstock for the sustainable production of lipids by L. starkeyi. The data obtained pave the way to further improve lipid production by designing a fed-batch process in bioreactor. Graphical abstract


Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 609 ◽  
Author(s):  
Niravkumar Mahendrasinh Kosamia ◽  
Mahdieh Samavi ◽  
Bijaya Kumar Uprety ◽  
Sudip Kumar Rakshit

The rapid growth of global biodiesel production requires simultaneous effective utilization of glycerol obtained as a by-product of the transesterification process. Accumulation of the byproduct glycerol from biodiesel industries can lead to considerable environment issues. Hence, there is extensive research focus on the transformation of crude glycerol into value-added products. This paper makes an overview of the nature of crude glycerol and ongoing research on its conversion to value-added products. Both chemical and biological routes of glycerol valorization will be presented. Details of crude glycerol conversion into microbial lipid and subsequent products will also be highlighted.


Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1009
Author(s):  
Gwon Woo Park ◽  
Seongsoo Son ◽  
Myounghoon Moon ◽  
Subin Sin ◽  
Kyoungseon Min ◽  
...  

Microbial lipid production from oleaginous yeasts is a promising process for the sustainable development of the microbial biodiesel industry. However, the feedstock cost poses an economic problem for the production of microbial biodiesel. After lipid extraction, yeast biomass can be used as an organic source for microbial biodiesel production. In this study, volatile fatty acids (VFAs), produced via anaerobic digestion of a lipid-extracted yeast (LEY) residue, were utilized as a carbon source for the yeast Cryptococcus curvatus. The response surface methodology was used to determine the initial pH and inoculum volume for the optimal VFA production. The experimental result for VFA concentration was 4.51 g/L at an initial pH of 9 and an inoculation 25%. The optimization results from the response surface methodology showed that the maximal VFA concentration was 4.58 g/L at an initial pH of 8.40 and an inoculation of 39.49%. This study indicates that VFAs from LEY can be used as a carbon source for microbial biodiesel production, with the potential to significantly reduce feedstock costs.


2020 ◽  
Vol 161 ◽  
pp. 91-97 ◽  
Author(s):  
Zhengang Miao ◽  
Xuemei Tian ◽  
Wenxing Liang ◽  
Yawen He ◽  
Guangyuan Wang

2013 ◽  
Vol 67 (8) ◽  
pp. 1802-1808 ◽  
Author(s):  
Jun-Xian Liu ◽  
Qin-Yan Yue ◽  
Bao-Yu Gao ◽  
Yan Wang ◽  
Qian Li ◽  
...  

In this paper, potato starch wastewater as culture medium was treated by the oleaginous yeast Lipomyces starkeyi to biosynthesize microbial lipid. The result indicated that carbon source types, carbon source concentration, nitrogen source types, nitrogen source concentration, inoculum size, and cultivation time all had a significant effect on cell growth and microbial lipid accumulation in batch cultures. A measure of 120 g/L of glucose concentration, 3.0 g/L of (NH4)2SO4 concentration, 10% inoculum size, and incubation time 96 h cultivated in a shaking flask at 30 °C were found to be the optimal conditions not only for cell growth but also for lipid synthesis. Under this condition, the cellular biomass and lipid content could reach 2.59 g/L and 8.88%, respectively. This work provides a new method for effective utilization of potato starch wastewater, which has particular social and economic benefits for yeast treatment technology.


2012 ◽  
Vol 106 ◽  
pp. 69-73 ◽  
Author(s):  
Jun-Xian Liu ◽  
Qin-Yan Yue ◽  
Bao-Yu Gao ◽  
Zuo-Hao Ma ◽  
Pei-Dong Zhang

RSC Advances ◽  
2016 ◽  
Vol 6 (32) ◽  
pp. 26752-26756 ◽  
Author(s):  
Xibin Zhang ◽  
Hongwei Shen ◽  
Xiaobing Yang ◽  
Qian Wang ◽  
Xue Yu ◽  
...  

Laminaria residues, major wastes from the kelp industry, can be effectively converted by oleaginous yeasts into microbial lipids as potential feedstock for biodiesel production.


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