Publications by authors named "Luis F Barahona-Pérez"

3 Publications

  • Page 1 of 1

Consolidated Bioprocess for Bioethanol Production from Raw Flour of Seeds Using the Native Strain of Bm-2.

Microorganisms 2019 Oct 23;7(11). Epub 2019 Oct 23.

Renewable Energy Department, Yucatan Center for Scientific Research, Merida 97302, Mexico.

Consolidated bioprocessing (CBP), which integrates biological pretreatment, enzyme production, saccharification, and fermentation, is a promising operational strategy for cost-effective ethanol production from biomass. In this study, the use of a native strain of (Bm-2) was evaluated for bioethanol production from in a CBP. The raw seed flour obtained from the ramon tree contained 61% of starch, indicating its potential as a raw material for bioethanol production. Quantitative assays revealed that the Bm-2 strain produced the amylase enzyme with activity of 193.85 U/mL. The Bm-2 strain showed high tolerance to ethanol stress and was capable of directly producing ethanol from raw flour at a concentration of 13 g/L, with a production yield of 123.4 mL/kg flour. This study demonstrates the potential of Bm-2 for starch-based ethanol production in a consolidated bioprocess to be implemented in the biofuel industry. The residual biomass after fermentation showed an average protein content of 22.5%, suggesting that it could also be considered as a valuable biorefinery co-product for animal feeding.
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http://dx.doi.org/10.3390/microorganisms7110483DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6920830PMC
October 2019

Hydrolysis of Agave fourcroydes Lemaire (henequen) leaf juice and fermentation with Kluyveromyces marxianus for ethanol production.

BMC Biotechnol 2014 Feb 14;14:14. Epub 2014 Feb 14.

Centro de Investigación Científica de Yucatán AC, Calle 43 No, 130 Col, Chuburná de Hidalgo, Mérida, Yucatán 97200, Mexico.

Background: Carbon sources for biofuel production are wide-ranging and their availability depends on the climate and soil conditions of the land where the production chain is located. Henequen (Agave fourcroydes Lem.) is cultivated in Yucatán, Mexico to produce natural fibers from the leaves, and a juice containing fructans is produced during this process. Fructans can be hydrolyzed to fructose and glucose and metabolized into ethanol by appropriate yeasts. In Mexico, different Agave species provide the carbon source for (distilled and non-distilled) alcoholic beverage production using the stem of the plant, whilst the leaves are discarded. In this work, we investigated the effect of thermal acid and enzymatic hydrolysis of the juice on the amount of reducing sugars released. Growth curves were generated with the yeasts Saccharomyces cerevisiae and Kluyveromyces marxianus and fermentations were then carried out with Kluyveromyces marxianus to determine alcohol yields.

Results: With thermal acid hydrolysis, the greatest increase in reducing sugars (82.6%) was obtained using 5% H2SO4 at 100°C with a 30 min reaction time. Statistically similar results can be obtained using the same acid concentration at a lower temperature and with a shorter reaction time (60°C, 15 min), or by using 1% H2SO4 at 100°C with a 30 min reaction time. In the case of enzymatic hydrolysis, the use of 5.75, 11.47 and 22.82 U of enzyme did not produce significant differences in the increase in reducing sugars. Although both hydrolysis processes obtained similar results, the difference was observed after fermentation. Ethanol yields were 50.3 ± 4 and 80.04 ± 5.29% of the theoretical yield respectively.

Conclusions: Final reducing sugars concentrations obtained with both thermal acid and enzymatic hydrolysis were similar. Saccharomyces cerevisiae, a good ethanol producer, did not grow in the hydrolysates. Only Kluyveromyces marxianus was able to grow in them, giving a higher ethanol yield with the enzymatic hydrolysate. The leaves account for a non-negligible weight of the total agave plant biomass, so this work complements the knowledge already developed on agave fermentations by making it possible to produce ethanol from almost the entire plant (stem and leaves).
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http://dx.doi.org/10.1186/1472-6750-14-14DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3932041PMC
February 2014

The green microalga Chlorella saccharophila as a suitable source of oil for biodiesel production.

Curr Microbiol 2011 Aug 3;63(2):151-7. Epub 2011 Jun 3.

Centro de Investigación Científica de Yucatán, Unidad de Biotecnología, Mérida, Mexico.

The aim of this study was to investigate the potential of the green microalga Chlorella saccharophila as a source of oil for biodiesel production. We evaluated for the first time, the effect of salinity and/or nitrogen depletion (ND) on cell growth, lipid accumulation and lipid profile in this microalga. The fatty acid methyl esters (FAME) identified for C. saccharophila in this study consisted of C-16:0, C-18:0, C-18:1 cis, and C-18:1 trans. Among these, C-18:1 (indicator of biodiesel quality) was the main FAME found, representing approximately 76 and 80% of total FAME under normal and ND growing conditions, respectively. Under a normal growing condition this microalga showed 154.63 mg l(-1) d(-1), 63.33 mg l(-1) d(-1), and 103.73 mg l(-1) of biomass productivity, lipid productivity, and FAME yield, respectively. The higher biomass productivity (159.58 mg l(-1) d(-1)), lipid productivity (99.33 mg l(-1) d(-1)), and FAME yield (315.53 mg l(-1)) were obtained under the ND treatment. In comparison to other related studies, our results suggest that C. saccharophila can be considered as a suitable source of oil for biodiesel production.
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http://dx.doi.org/10.1007/s00284-011-9956-7DOI Listing
August 2011