Proteomics Reveals an Increase in the Abundance of Glycolytic and Ethanolic Fermentation Enzymes in Developing Sugarcane Culms During Sucrose Accumulation

Sugarcane is an economically important crop contributing to the sugar and ethanol production of the world with 80 and 40%, respectively. Despite its importance as the main crop for sugar production, the mechanisms involved in the regulation of sucrose accumulation in sugarcane culms are still poorly understood. The aim of this work was to compare the quantitative changes of proteins in juvenile and maturing internodes at three stages of plant development. Label-free shotgun proteomics was used for protein profiling and quantification in internodes 5 (I5) and 9 (I9) of 4-, 7-, and 10-month-old-plants (4M, 7M, and 10M, respectively). The I9/I5 ratio was used to assess the differences in the abundance of common proteins at each stage of internode development. I9 of 4M plants showed statistically significant increases in the abundance of several enzymes of the glycolytic pathway and proteoforms of alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC). The changes in content of the enzymes were followed by major increases of proteins related to O2 transport like hemoglobin 2, ROS scavenging enzymes, and enzymes involved in the ascorbate/glutatione system. Besides, intermediates from tricarboxylic acid cycle (TCA) were reduced in I9-4M, indicating that the increase in abundance of several enzymes involved in glycolysis, pentose phosphate cycle, and TCA, might be responsible for higher metabolic flux, reducing its metabolites content. The results observed in I9-4M indicate that hypoxia might be the main cause of the increased flux of glycolysis and ethanolic fermentation to supply ATP and reducing power for plant growth, mitigating the reduction in mitochondrial respiration due to the low oxygen availability inside the culm. As the plant matured and sucrose accumulated to high levels in the culms, the proteins involved in glycolysis, ethanolic fermentation, and primary carbon metabolism were significantly reduced.

Peculiar Response in the Co-Culture Fermentation of Leuconostoc mesenteroides and Lactobacillus plantarum for the Production of ABE Solvents

Two bacterial strains (CL11A and CL11D) that are capable of ABE fermentation, identified as Leuconostoc mesenteroides and Weissella cibari, were isolated from the soil surrounding the roots of bean plants. Another strain (ZM 3A), identified as Lactobacillus plantarum, which is capable of purely ethanolic fermentation was isolated from sugarcane. Glucose was used as a standard substrate to investigate the performance of these strains in mono—and co-culture fermentation for ABE production. The performance parameters employed in this study were substrate degradation rates, product and metabolite yields, pH changes and microbial growth rates. Both ABE isolates were capable of producing the three solvents but Leuconostoc mesenteroides had a higher specificity for ethanol than Weissella cibari. The co-culturing of Leuconostoc mesenteroides and Lactobacillus plantarum enhanced ethanol production at the expense of both acetone and butanol, and also influenced the final substrate consumption rate and product yield. The experiments indicated the potential of these niche environments for the isolation of ABE-producing microorganisms. This study contributes to the formulation of ideal microbial co-culture and consortia fermentation, which seeks to maximize the yield and production rates of favored products.

Bioethanol Production of Cellulase Producing Bacteria from Soils of Agrowaste Field

With decades of studies on cellulose bioconversion, cellulases have been playing an important role in producing fermentable sugars from lignocellulosic biomass. Copious microorganisms that are able to degrade cellulose have been isolated and identified. The present study has been undertaken to isolate and screen the cellulase producing bacteria from soils of agrowaste field. Cellulase production has been qualitatively analyzed in carboxy methylcellulose (CMC) agar medium after congo red staining and NaCl treatment by interpretation with zones around the potent colonies. Out of the seven isolates, only two showed cellulase production. The morphogical and molecular characterization revealed its identity as Escherichia coli and Staphylococcus aureus. The potential of organisms for bioethanol production has been investigated using two substrates, namely, paper and leaves by subjecting with a pre-treatment process using acid hydrolysis to remove lignin which acts as physical barrier to cellulolytic enzymes. Ethanolic fermentation was done using Saccharomyces cerevisiae for 24-48 h and then the bioethanol produced was qualitatively proved by iodoform assay. These finding proves that ethanol can be made from the agricultural waste and the process is recommended as a means of generating wealth from waste.

Interaction between S. cerevisiae MONA, PE-2, CAT-1 and ATCC in fermentation sugar cane broth

The diversity microbial in ethanolic fermentation generate different behavior metabolic that depended on the microorganisms present. Some kinetic parameters can tell how interactions between microorganisms are occurring in fermentation and can also predict your metabolic behaviors. However, there are little studys about the influence of interactions microbial on kinetic parameters in fermentation sugar cane. Therefore, this work aimed to understand the influence of the yeast strain Saccharomyces cerevisiae CAT-1, MONA, PE-2 and ATCC in the production of biomass, ethanol, glycerol and sugar consumption, as well as to evaluate the kinetic parameters by means of response surface methodology for mixing. From the biomass models generated, it was observed that the yeasts ATCC and MONA when in the presence of CAT-1 and PE-2 showed antagonisms. For the ethanol, the synergistic effect was verified for the mixture MONA/ATCC and CAT-1/PE-2 being that CAT-1 and PE-2 were the yeasts that strongly favored the ethanol production. It stands out yeast MONA due to having lower glycerol production, character desirable in the sugar and alcohol industry. Thus, it is clear that from the analysis employed it was possible to infer about the kinetic behavior of the yeasts in pure cultures as well as the effect of the interaction between them during the cultivation.

Efficiency and Fermentative Yield of Sweet Sorghum Using Cat-1 And Pedra-2

Background: The increase in demand for fuels has intensified the search for renewable energy sources, mainly biomass, with sugarcane being the most important factor in the production of bioethanol. In addition, sorghum cultivation presents high potential mainly for using the same industrial production complex and being processed in the off-season of sugarcane. However, information on the chemical and technological characteristics of sweet sorghum in the national literature is scarce. These are of extreme importance considering the preparation and adaptation stages of musts and yeasts, preceding the process of ethanolic fermentation. The objective of this research was to evaluate the fermentation process of the CVSW80007 genotypes; CVWS80147 and BRS610 in laboratory scale, evaluating the performance of CAT-1 and PEDRA-2 yeasts by determining yields and fermentative efficiencies and alcohol production (L.ha-1 and L.t-1). Results: The experimental design was the randomized blocks in a 3x2x6 Factorial model in the fermentation process (for each of the yeasts studied). The results indicated that CAT-1 and PEDRA-2 yeasts demonstrate similar behavior, being efficient in the fermentation process. The fermentation of must was prepared from stalks with leaves and without leaves (135 days after sowing) of the three genotypes, results in 47.0 and 39.8 L.t-1 ethanol, respectively, using sweet sorghum.Conclusions: The conditions studied on a laboratory scale demonstrate that the different sweet sorghum genotypes have potential for ethanol production, with the stalks with leaves and panicles increasing the alcohol content and fermentative efficiency.

Potential of Candida glabrata from ragi as a bioethanol producer using selected carbohydrate substrates

Vincent M, Johnny Q, Adeni DSA, Suhaili N. 2020. Potential of Candida glabrata from ragi as a bioethanol producer using selected carbohydrate substrates. Nusantara Bioscience 12: 1-10. The flexibility and efficiency of fermenting microorganisms to convert substrates to ethanol are important factors in achieving high bioethanol yields during ethanolic fermentation. In this study, Candida glabrata, a common yeast found in fermented food, was evaluated in terms of its capability to produce ethanol using different types of carbohydrates, which included simple saccharides (glucose, maltose, sucrose), polysaccharides (starch and cellulose) and complex carbohydrates (total sago effluent, TSE). Our results indicated that C. glabrata was able to efficiently produce ethanol from glucose at 79.84% TEY (Theoretical Ethanol Yield). The ethanol production from sucrose was low, which was only 6.44% TEY, while no ethanol was produced from maltose. Meanwhile, for complex carbohydrate substrates such as starch and cellulose, ethanol was produced only when supplementary enzymes were introduced. Simultaneous Saccharification and Fermentation (SSF) of starch dosed with amylases resulted in an ethanol yield of 55.08% TEY, whilst SSF of cellulose dosed with cellulases yielded a TEY of 31.41%. When SSF was performed on TSE dosed with amylases and cellulases, the highest ethanol production was recorded within 24 h, with a yield of 23.36% TEY. Lactic acid and acetic acid were found to be at minimal levels throughout the fermentation period, indicating an efficient ethanol conversion. A notable increase in C. glabrata biomass was observed in cultures fed with glucose, starch (with supplementary amylases), and TSE (with supplementary amylases and cellulases). The current study indicates that C. glabrata can be used for bioethanol production from glucose, polysaccharides, and complex starchy lignocellulosic substrates such as TSE via SSF.