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1.
Ciênc. rural (Online) ; 52(2): e20210068, 2022. tab, graf, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1286060

ABSTRACT

This research valorized Pachira aquatica Aubl.'s fruit shells (PAS) through its energetic characterization and flash pyrolysis for biofuels or chemicals production. The characterization was performed through proximate and ultimate analysis, bulk density, higher heating value (HHV), hemicellulose, cellulose and lignin content, thermogravimetric analysis and absorption spectra in the infrared region obtained by Fourier-transform infrared spectroscopy technique (FTIR). The analytical flash pyrolysis was performed at 500°C in a Py-5200 HP-R coupled to a gas chromatograph (Py-GC/MS). The PAS biomass presents potential for thermochemical energy conversion processes due to its low moisture and ash content, 76.90% of volatile matter, bulk density of 252.6 kg/m3 and HHV of 16.24 MJ/kg. Flash pyrolysis products are mostly phenols or light organic acids derived from the decomposition of polysaccharides. Results confirmed the potential of PAS to produce bio-phenolics, such as 4-methoxyphenol which is an important active ingredient for skin depigmentation used in drugs and cosmetics, and as phenolic extract that can be used as a precursor to resins, applications that convert this forest waste into bio products for industry into a green circular economy.


Este trabalho teve como objetivo a valorização das cascas dos frutos da Pachira aquatica Aubl. (PAC) através da sua caracterização energética e pirólise flash para produção de biocombustíveis ou produtos químicos. A caracterização foi realizada através de análises imediata e final, densidade aparente, poder calorífico superior (PCS), conteúdos de hemicelulose, celulose e lignina, análise termogravimétrica e espectros de absorção na região do infravermelho obtidos pela técnica de espectroscopia no infravermelho com transformada de Fourier (FTIR). A pirólise flash analítica foi realizada a 500 °C em equipamento Py-5200 HP-R acoplado a um cromatógrafo à gás (Py-GC/MS). A biomassa das PAC apresenta potencial para processos de conversão termoquímica de energia devido ao seu baixo teor de umidade e cinzas, além de 76,90% de materiais voláteis, densidade aparente de 252,6 kg/m3 e PCS igual a 16,24 MJ / kg. Os produtos da pirólise rápida são principalmente fenóis ou ácidos orgânicos leves derivados da decomposição de polissacarídeos. Os resultados confirmam o potencial das PAC para produzir bio-fenólicos, como o 4-metoxifenol que é um importante ingrediente ativo para despigmentação da pele usado em medicamentos e cosméticos, e como extrato fenólico que pode ser usado como precursor de resinas. Estas aplicações convertem esses resíduos florestais em produtos biológicos para a indústria em uma economia circular verde.


Subject(s)
Pyrolysis , Biomass , Bombacaceae , Fruit/chemistry , Lignin , Polysaccharides , Biofuels
2.
Electron. j. biotechnol ; 50: 29-36, Mar. 2021. tab, graf
Article in English | LILACS | ID: biblio-1292313

ABSTRACT

BACKGROUND: Lignocellulose is considered a renewable organic material, but the industrial production of biofuel from lignocellulose is challenging because of the lack of highly active hydrolytic enzymes. The guts of herbivores contain many symbiotic microorganisms that have evolved to hydrolyze plant lignocellulose. Chinese bamboo rats mainly consume high-fiber foods, indicating that some members of the intestinal tract microbiota digest lignocellulose, providing these rats with the energy required for growth. RESULTS: Here, we used metagenomics to analyze the diversity and functions of the gut microbiota in Chinese bamboo rats. We identified abundant populations of lignocellulose-degrading bacteria, whose main functions involved carbohydrate, amino acid, and nucleic acid metabolism. We also found 587 carbohydrate-active enzyme genes belonging to different families, including 7 carbohydrate esterase families and 21 glycoside hydrolase families. The glycoside hydrolase 3, glycoside hydrolase 1, glycoside hydrolase 43, carbohydrate esterase 4, carbohydrate esterase 1, and carbohydrate esterase 3 families demonstrated outstanding performance. CONCLUSIONS: The microbes and enzymes identified in our study expand the existing arsenal of proficient degraders and enzymes for lignocellulosic biofuel production. This study also describes a powerful approach for targeting gut microbes and enzymes in numerous industries.


Subject(s)
Animals , Rats , Cecum/enzymology , Enzymes/metabolism , Lignin/metabolism , Cecum/microbiology , Cellulose/metabolism , Bacteroidetes , Biofuels , Metagenomics , Firmicutes , Gastrointestinal Microbiome
3.
Electron J Biotechnol ; 49: 34-41, Jan. 2021. tab, graf
Article in English | LILACS | ID: biblio-1291638

ABSTRACT

BACKGROUND: This work studied how the exposure to an unusual substrate forced a change in microbial populations during anaerobic fermentation of crude glycerol, a by-product of biodiesel production, with freshwater sediment used as an inoculum. RESULTS: The microbial associations almost completely (99.9%) utilized the glycerol contained in crude glycerol 6 g L 1 within four days, releasing gases, organic acids (acetic, butyric) and alcohols (ethanol, n-butanol) under anaerobic conditions. In comparison with control medium without glycerol, adding crude glycerol to the medium increased the amount of ethanol and n-butanol production and it was not significantly affected by incubation temperature (28 C or 37 C), nor incubation time (4 or 8 d), but it resulted in reduced amount of butyric acid. Higher volume of gas was produced at 37 C despite the fact that the overall bacterial count was smaller than the one measured at 20 C. Main microbial phyla of the inoculum were Actinobacteria, Proteobacteria and Firmicutes. During fermentation, significant changes were observed and Firmicutes, especially Clostridium spp., began to dominate, and the number of Actinobacteria and Gammaproteobacteria decreased accordingly. Concentration of Archaea decreased, especially in medium with crude glycerol. These changes were confirmed both by culturing and culture-independent (concentration of 16S rDNA) methods. CONCLUSIONS: Crude glycerol led to the adaptation of freshwater sediment microbial populations to this substrate. Changes of microbial community were a result of a community adaptation to a new source of carbon.


Subject(s)
Bacteria/isolation & purification , Geologic Sediments/microbiology , Fresh Water/microbiology , Glycerol/metabolism , Bacteria/metabolism , Adaptation, Biological , Biofuels , Fermentation , Real-Time Polymerase Chain Reaction/methods , Anaerobiosis
4.
Braz. arch. biol. technol ; 64: e21200781, 2021. tab
Article in English | LILACS | ID: biblio-1339313

ABSTRACT

Abstract Fruit juice industry generates massive amount of lignocellulosic by-products annually which are excellent raw materials for bioethanol production. In the current study, bioethanol production from apricot (Prunus armeniaca) pomace by Kluyveromyces marxianus was investigated for the first time. Some key parameters for fermentation such as pretreatment methods, biomass and cellulase loading and time, were optimized. Kluyveromyces marxianus produced 30.09 g/L ethanol in the 20% washed apricot pomace and 120 FPU/g cellulose enzyme loading. The highest theoretical yield and Y P/S values were also observed as 94.7% and 0.50 g/g, respectively, when 15 FPU/g cellulose enzyme was used. These results depict that apricot pomace is a promising feedstock for bioethanol production.


Subject(s)
Kluyveromyces , Biofuels , Renewable Energy , Prunus armeniaca
5.
Braz. arch. biol. technol ; 64: e21200531, 2021. tab, graf
Article in English | LILACS | ID: biblio-1249210

ABSTRACT

Abstract Microalgae research has attracted interest worldwide and in order to advance algal biotechnology in Brazil, government has been funding several projects. In the last 10 years, two main funds were provided by the National Council of Scientific and Technological Development (CNPq) agency to researchers in Brazil, who study the potential uses of microalgae for biomass, bioproducts and biofuels production. These funded projects addressed aspects of algal strain identification, development of algal cultivation techniques, designing photobioreactors and raceway ponds, modeling harvesting and dewatering process, maximizing biomass and oil productivities, characterizing chemical composition with different extractions systems and determining physiochemical properties of biodiesel. This review presents the state of art of algal research conducted by Brazilian institutions. Special attention is given to the recent progress on microalgal cultivation, high-value products extracted from microalgae and potential biofuels production. This review may serve as a policy instrument for planning next steps for algal research in Brazil as well as for attracting attention from international researchers who work with microalgae and would like to pursue a future partnership on algal research with Brazilian research institutions.


Subject(s)
Biotechnology/methods , Biofuels , Microalgae , Photobioreactors
6.
Braz. arch. biol. technol ; 64: e21200102, 2021. tab, graf
Article in English | LILACS | ID: biblio-1278441

ABSTRACT

Abstract The synergism of food waste associated with swine manure can provide an increase in biogas production, besides promoting greater stability in the anaerobic co-digestion process. To verify this effect, co-digestion tests were performed in two reactors, one with agitation, and the other without agitation. In both systems, gasometers were used to measure biogas production in an experiment lasting two hydraulic retention times (HRT). On each feeding day, the temperatures of the ambient and of the effluent taken from the reactors were measured, and samples of the food waste and effluent were collected to perform analysis of pH, total solids (TS), volatile solids (VS), fixed solids (FS), volatile acidity (AV), and total alkalinity (TA). In addition, the chemical oxygen demand (COD) was determined every five days, and gas composition was determined at the beginning of the second HRT. As important results, in both reactors a decrease in pH was verified due to the weakening of the buffer effect of the medium. This was due to the low alkalinity found in the food waste, causing an increase in acidity in the contents of the reactors. The volume of biogas produced was higher in the reactor with agitation, which meant an increased efficiency of the process. Finally, a low methane content was verified through chromatographic analyses, indicating a reduction in the activity of the microorganisms present in the medium. Thus, it is concluded that agitation linked to anaerobic co-digestion of swine manure with food waste exerted a positive effect on biogas production.


Subject(s)
Food Wastefulness , Biofuels , Garbage , Anaerobic Digestion , Activated Sludges
7.
Chinese Journal of Biotechnology ; (12): 1721-1736, 2021.
Article in Chinese | WPRIM | ID: wpr-878663

ABSTRACT

Higher alcohols that contain more than two carbon atoms have better fuel properties than ethanol, making them important supplements and alternatives to fossil fuels. Using microbes to produce higher alcohols from renewable biomass can alleviate the current energy and environmental crises, and has become a major future direction for green biomanufacturing. Since natural microbes can only produce a few higher alcohols in small amounts, it is necessary to reconstruct the synthetic pathways for higher alcohols in model industrial strains through metabolic engineering and synthetic biology to overcome the metabolic bottlenecks. A series of milestones have been accomplished in past decades. The authors of this review have witnessed the entire journey of this field from its first success to the leaping development. On the 30th anniversary of the founding of the discipline of metabolic engineering, this review dates back to the great milestones in achieving heterologous production of higher alcohols in non-native strains. The design and optimization of high alcohol biosynthetic pathways, the expansion of feedstock, the engineering of host strains and the industrialization process are summarized. This review aims to draw further attention to microbial synthesis of higher alcohols, inspire the development of novel techniques and strategies of metabolic engineering, and promote the innovation and upgrade of China's biofuel industry.


Subject(s)
Alcohols , Biofuels , Biosynthetic Pathways , Ethanol , Metabolic Engineering , Synthetic Biology
8.
Chinese Journal of Biotechnology ; (12): 1471-1476, 2021.
Article in Chinese | WPRIM | ID: wpr-878649

ABSTRACT

Metabolic engineering is the use of recombinant DNA technology, synthetic biology and genome editing to modify the cellular networks including metabolic, gene regulatory, and signaling networks of an organism. It can achieve the desirable goals such as enhanced production of metabolites, and improve the capability of biomanufacturing pharmaceuticals, biofuels and biochemicals as well as other biotechnology products. In order to comprehend the status of metabolic engineering in past 30 years, we published this special issue to review the progress and trends of metabolic engineering from the four aspects of overall development, key technologies, host engineering and product engineering, respectively, for laying the foundation for the further development of metabolic engineering.


Subject(s)
Anniversaries and Special Events , Biofuels , Biotechnology , Metabolic Engineering , Synthetic Biology
9.
Chinese Journal of Biotechnology ; (12): 2753-2764, 2021.
Article in Chinese | WPRIM | ID: wpr-887838

ABSTRACT

Biodiesel is an alternative fuel to addressing the energy shortage problem. Microbial lipids have attracted widespread attention as one of the potential feed-stocks for cost-effective and efficient biodiesel production. However, the large-scale production of microbial lipids is hampered by the complexity and the high cost of aseptic culturing approach. Metschnikowia pulcherrima is an oleaginous yeast with strong environmental adaptability. It is capable of utilizing a wide spectrum of substrates, and can be cultured under non-sterile conditions. Therefore, this yeast has great potential to replace the traditional oleaginous microorganisms, particularly in the area of recycling wastewater and solid waste for the production of biodiesel. Based on the analysis of lipid production and application conditions of M. pulcherrima, this review summarized the unique advantages of M. pulcherrima and the key factors affecting lipids production. We further discussed the feasibility of cultivating M. pulcherrima on various organic wastes under non-sterile conditions for lipids production. Moreover, we analyzed the challenges associated with M. pulcherrima's in the yield and mechanism for lipids production, and proposed perspectives for how to achieve efficient biodiesel production using this yeast.


Subject(s)
Biofuels , Candida , Lipids , Metschnikowia , Yeasts
10.
Chinese Journal of Biotechnology ; (12): 1042-1057, 2021.
Article in Chinese | WPRIM | ID: wpr-878613

ABSTRACT

Effective utilization of xylose is a basis for economic production of biofuels or chemicals from lignocellulose biomass. Over the past 30 years, through metabolic engineering, evolutionary engineering and other strategies, the metabolic capacity of xylose of the traditional ethanol-producing microorganism Saccharomyces cerevisiae has been significantly improved. In recent years, the reported results showed that the transcriptome and metabolome profiles between xylose and glucose metabolism existed significant difference in recombinant yeast strains. Compared with glucose, the overall process of xylose metabolism exhibits Crabtree-negative characteristics, including the limited glycolytic pathway activity, which reduces the metabolic flux of pyruvate to ethanol, and the enhanced cytosolic acetyl-CoA synthesis and respiratory energy metabolism. These traits are helpful to achieve efficient synthesis of downstream products using pyruvate or acetyl-CoA as precursors. This review provides a detailed overview on the modification and optimization of xylose metabolic pathways in S. cerevisiae, the characteristics of xylose metabolism, and the construction of cell factories for production of chemicals using xylose as a carbon source. Meanwhile, the existed difficulties and challenges, and future studies on biosynthesis of bulk chemicals using xylose as an important carbon source are proposed.


Subject(s)
Biofuels , Ethanol , Fermentation , Metabolic Engineering , Saccharomyces cerevisiae/genetics , Xylose
11.
Chinese Journal of Biotechnology ; (12): 816-830, 2021.
Article in Chinese | WPRIM | ID: wpr-878598

ABSTRACT

Due to abundant availability of shale gas and biogas, methane has been considered as one of the most potential carbon sources for industrial biotechnology. Methanotrophs carrying the native methane monooxygenase are capable of using methane as a sole energy and carbon source, which provides a novel strategy for reducing greenhouse gas emission and substituting edible substrates used in bioconversion processes. With the rapid development of genetic engineering tools and biosynthesis techniques, various strategies for improving the efficiency of methane bioconversion have been achieved to produce a variety of commodity bio-based products. Herein, we summarize several important aspects related with methane utilization and metabolic engineering of methanotrophs, including the modification of methane oxidation pathways, the construction of efficient cell factories, and biosynthesis of chemicals and fuels. Finally, the prospects and challenges of the future development of methane bioconversion are also discussed.


Subject(s)
Biofuels , Biotechnology , Metabolic Engineering , Methane , Oxidation-Reduction
12.
Chinese Journal of Biotechnology ; (12): 806-815, 2021.
Article in Chinese | WPRIM | ID: wpr-878597

ABSTRACT

Yeast are comprised of diverse single-cell fungal species including budding yeast Saccharomyces cerevisiae and various nonconventional yeasts. Budding yeast is well known as an important industrial microorganism, which has been widely applied in various fields, such as biopharmaceutical and health industry, food, light industry and biofuels production. In the recent years, various yeast strains from different ecological environments have been isolated and characterized. Novel species have been continuously identified, and strains with diverse physiological characteristics such as stress resistance and production of bioactive compounds were selected, which proved abundant biodiversity of natural yeast resources. Genome mining of yeast strains, as well as multi-omics analyses (transcriptome, proteome and metabolome, etc.) can reveal diverse genetic diversity for strain engineering. The genetic resources including genes encoding various enzymes and regulatory proteins, promoters, and other elements, can be employed for development of robust strains. In addition to exploration of yeast natural diversity, phenotypes that are more suitable for industrial applications can be obtained by generation of a variety of genetic diversity through mutagenesis, laboratory adaptation, metabolic engineering, and synthetic biology design. The optimized genetic elements can be used to efficiently improve strain performance. Exploration of yeast biodiversity and genetic diversity can be employed to build efficient cell factories and produce biological enzymes, vaccines, various natural products as well as other valuable products. In this review, progress on yeast diversity is summarized, and the future prospects on efficient development and utilization of yeast biodiversity are proposed. The methods and schemes described in this review also provide a reference for exploration of diversity of other industrial microorganisms and development of efficient strains.


Subject(s)
Biodiversity , Biofuels , Industrial Microbiology , Metabolic Engineering , Saccharomyces cerevisiae/genetics , Synthetic Biology
13.
Article in Chinese | WPRIM | ID: wpr-878539

ABSTRACT

Lignocellulose can be hydrolyzed by cellulase into fermentable sugars to produce hydrogen, ethanol, butanol and other biofuels with added value. Pretreatment is a critical step in biomass conversion, but also generates inhibitors with negative impacts on subsequent enzymatic hydrolysis and fermentation. Hence, pretreatment and detoxification methods are the basis of efficient biomass conversion. Commonly used pretreatment methods of lignocellulose are chemical and physic-chemical processes. Here, we introduce different inhibitors and their inhibitory mechanisms, and summarize various detoxification methods. Moreover, we propose research directions for detoxification of inhibitors generated during lignocellulose pretreatment.


Subject(s)
Biofuels , Biomass , Fermentation , Hydrolysis , Lignin/metabolism
14.
Arq. bras. med. vet. zootec. (Online) ; 72(6): 2348-2354, Nov.-Dec. 2020. tab
Article in English | LILACS, VETINDEX | ID: biblio-1142292

ABSTRACT

The energetic values of crude glycerin (CG) were determined for broilers at different ages using the method proposed by Matterson and by polynomial regressions. Two trials were performed with broilers from 11 to 21 and from 31 to 41 days of age. The birds were distributed in a completely randomized experimental design with a reference ration (RR), without CG, and three ration tests with replacement of 5%, 10%, and 15% of RR by CG. The metabolizable energy values were calculated by the Matterson method, and the apparent metabolizable energy (AME) values were used in polynomial regression analysis. The mean values of AME, apparent corrected for nitrogen balance (AMEn), metabolizable coefficient of gross energy (CAMEB), and corrected for nitrogen balance (CAMEBn) of CG, for the phase from 11 to 21 days by the Matterson method were 10.08 MJ kg-1, 10.04 MJ kg-1, 67.06%, and 66.74%, respectively. The inclusion of CG presented an increasing linear effect for CAMEB and CAMEBn in this period. From 31 to 41 days, these values were 10.38 MJ kg-1, 10.27 MJ kg-1, 69.02%, and 62.24%, respectively. The predicted AMEn value through the polynomial regression equations was 10.49 MJ kg-1 and 10.18 MJ kg-1, respectively. According to the equations proposed by Matterson, the crude glycerin EMAn values for broilers from 11 to 21 and 31 to 41 days of age were 10.04 MJ kg-1 and 10.26 MJ kg-1, respectively. According to Adeola's method the AMEn values were 10.49 and 10.20 MJ kg-1 for each phase.(AU)


Os valores energéticos da glicerina bruta (GB) foram determinados para frangos de corte em diferentes idades, por meio da utilização do método proposto por Matterson e de regressões polinomiais. Foram realizados dois ensaios: de 11 a 21 dias e de 31 a 41 dias de idade das aves; em ambos, as aves foram distribuídas em um delineamento experimental inteiramente ao acaso, com uma ração referência (RR), sem GB, e três rações testes com substituição de 5%, 10% e 15% da RR por GB. Foram calculados os valores de energia metabolizável pelo método de Matterson, sendo os valores de energia metabolizável aparente (EMA) utilizados na análise de regressão polinomial. Os valores médios da EMA corrigida pelo balanço de nitrogênio (EMAn), o coeficiente de metabolizabilidade da EB (CMAEB) e o corrigido para o balanço de nitrogênio (CMAEBn) da GB, na matéria natural, para a fase de 11 a 21 dias, pelo método de Matterson, foram de 10,08 MJ kg-1, 10,04 MJ kg-1, 67,06% e 66,74%, respectivamente. A inclusão de GB apresentou um efeito linear crescente para os CMAEB e os CMAEBn. Na fase de 31 a 41 dias, foram de 10,38 MJ kg-1, 10,27 MJ kg-1, 69,02% e 62,24%, respectivamente. Por meio das equações de regressões polinomiais, o valor de EMAn estimada foi de 10,49 MJ kg-1 e 10,18 MJ kg-1, respectivamente. Os valores de EMAn da GB para as idades 11 a 21 e 31 a 41 dias foram de 10,04 MJ kg-1 e 10,26 MJ kg-1, respectivamente. De acordo com as equações propostas por Matterson e com o método de Adeola, os valores de EMAn foram 10,49 e 10,20 MJ kg-1 para cada fase.(AU)


Subject(s)
Animals , Chickens/metabolism , Biofuels/analysis , Glycerol/administration & dosage , Poultry/growth & development
15.
Electron. j. biotechnol ; 44: 60-68, Mar. 2020. tab, graf, ilus
Article in English | LILACS | ID: biblio-1087705

ABSTRACT

Background: Oleaginous yeasts can be grown on different carbon sources, including lignocellulosic hydrolysate containing a mixture of glucose and xylose. However, not all yeast strains can utilize both the sugars for lipogenesis. Therefore, in this study, efforts were made to isolate dual sugar-utilizing oleaginous yeasts from different sources. Results: A total of eleven isolates were obtained, which were screened for their ability to utilize various carbohydrates for lipogenesis. One promising yeast isolate Trichosporon mycotoxinivorans S2 was selected based on its capability to use a mixture of glucose and xylose and produce 44.86 ± 4.03% lipids, as well as its tolerance to fermentation inhibitors. In order to identify an inexpensive source of sugars, nondetoxified paddy straw hydrolysate (saccharified with cellulase), supplemented with 0.05% yeast extract, 0.18% peptone, and 0.04% MgSO4 was used for growth of the yeast, resulting in a yield of 5.17 g L−1 lipids with conversion productivity of 0.06 g L−1 h−1 . Optimization of the levels of yeast extract, peptone, and MgSO4 for maximizing lipid production using Box­Behnken design led to an increase in lipid yield by 41.59%. FAME analysis of single cell oil revealed oleic acid (30.84%), palmitic acid (18.28%), and stearic acid (17.64%) as the major fatty acids. Conclusion: The fatty acid profile illustrates the potential of T. mycotoxinivorans S2 to produce single cell oil as a feedstock for biodiesel. Therefore, the present study also indicated the potential of selected yeast to develop a zero-waste process for the complete valorization of paddy straw hydrolysate without detoxification


Subject(s)
Trichosporon/metabolism , Oryza , Xylose/isolation & purification , Trichosporon/chemistry , Oils/chemistry , Lipogenesis , Biofuels , Fermentation , Glucose/isolation & purification , Hydrolysis , Lignin/metabolism , Lipids/biosynthesis
16.
Arq. bras. med. vet. zootec. (Online) ; 72(1): 243-252, Jan.-Feb. 2020. tab
Article in Portuguese | LILACS, VETINDEX | ID: biblio-1088938

ABSTRACT

O objetivo deste estudo foi avaliar o perfil de ácidos graxos (AG) do leite de vacas alimentadas com dietas à base de silagem de milho contendo 0% e 8,9% de glicerina bruta (GB) na matéria seca (MS). Foram utilizadas 18 vacas Holandês x Gir com 48±18 dias em lactação, produzindo 19,8±4,9kg/dia de leite. Utilizou-se delineamento de blocos ao acaso, com nove vacas/tratamento e duas medidas repetidas no tempo, com os resultados analisados por modelos mistos. A inclusão de GB na dieta não alterou a ingestão de MS, mas reduziu os consumos dos AG oleico, linoleico e α-linolênico. Os teores dos AG mirístico, palmítico, rumênico, vacênico, esteárico, oleico, linoleico, α-linolênico e CLA trans-10 cis-12 na gordura do leite foram semelhantes entre dietas. A inclusão de GB reduziu os teores dos AG elaídico e C18:1 trans-10 e aumentou os teores dos AG de cadeia ímpar linear e do ácido láurico. Não houve efeito da inclusão da GB sobre os índices de aterogenicidade e trombogenicidade da gordura do leite. Concluiu-se que a inclusão de glicerina bruta em dieta à base de silagem de milho não afetou a qualidade nutricional da gordura do leite de vacas Holandês x Gir.(AU)


The objective of this study was to evaluate the milk fatty acid (FA) composition of cows fed corn silage-based diets containing 0% and 8.9% of crude glycerin (GB) on a dry matter (DM) basis. Eighteen Holstein x Gyr cows with 48±18 days in milk and producing 19.8±4.9kg milk/day were used in the study. The experimental design was a randomized block with nine cows per treatment and two repeated measures. Results were analyzed using mixed models. The milk fat contents of myristic, palmitic, rumenic, vaccenic, estearic, oleic, linoleic, α-linolenic, and trans-10 cis-12 CLA were similar between diets. Dietary inclusion of GB decreased elaidic and trans-10 C18:1, and increased lauric acid and odd linear-chain FA contents in milk fat. Both atherogenicity and trombogenicity indices were unaffected by GB inclusion. It was concluded that GB inclusion in corn silage-based diets had no effect on the nutritional quality of milk fat from Holstein x Gyr dairy cows.(AU)


Subject(s)
Animals , Female , Cattle , Silage , Milk/chemistry , Fatty Acids/analysis , Glycerol/administration & dosage , Biofuels , Animal Feed
17.
Braz. arch. biol. technol ; 63: e20190185, 2020. tab, graf
Article in English | LILACS | ID: biblio-1132193

ABSTRACT

Abstract The second-generation bioethanol employs lignocellulosic materials degraded by microbial cellulases in their production. The fungus Trichoderma reesei is one of the main microorganisms producing cellulases, and its genetic modification can lead to the optimization in obtaining hydrolytic enzymes. This work carried out the deletion of the sequence that encodes the zinc finger motif of the transcription factor ACE1 (cellulase expression repressor I) of the fungus T. reesei RUT-C30. The transformation of the RUT-C30 lineage was confirmed by amplification of the 989 bp fragment relative to the selection marker, and by the absence of the zinc finger region amplification in mutants, named T. reesei RUT-C30Δzface1. The production of cellulases by mutants was compared to RUT-C30 and measured with substrates carboxymethylcellulose (CMC), microcrystalline cellulose (Avicel®) and Whatman filter paper (PF). The results demonstrated that RUT-C30Δzface1 has cellulolytic activity increased 3.2-fold in Avicel and 2.1-fold in CMC and PF. The mutants presented 1.4-fold higher sugar released in the hydrolysis of the biomass assays. These results suggest that the partial deletion of ace1 gene is an important strategy in achieving bioethanol production on an industrial scale at a competitive price in the fuel market.


Subject(s)
Trichoderma/enzymology , Cellulase/biosynthesis , Zinc Fingers , Biomass , Ethanol , Biofuels
18.
Chinese Journal of Biotechnology ; (12): 2755-2766, 2020.
Article in Chinese | WPRIM | ID: wpr-878527

ABSTRACT

Consolidated bioprocessing (CBP) is a multi-step process in a bioreactor, which completes hydrolase production, enzymatic hydrolysis, and microbial fermentation. It is considered to be the most promising process for the production of second-generation biofuels because of its simple steps and low cost. Due to the complexity of lignocellulose degradation and the butanol synthesis pathway, few wild microorganisms can directly utilize lignocellulose to synthesize butanol. With the development of synthetic biology, single-bacterium directly synthesizes butanol using lignocellulose by introducing a butanol synthesis pathway in the cellulolytic Clostridium. However, there are still some problems such as heavy metabolic load of single bacterium and low butanol yield. Co-culture can relieve the metabolic burden of single bacterium through the division of labor in different strains and can further improve the efficiency of butanol synthesis. This review analyzes the recent research progress in the synthesis of biobutanol using lignocellulose by consolidated bioprocessing from both the single-bacterium strategy and co-culture strategy, to provide a reference for the research of butanol and other biofuels.


Subject(s)
1-Butanol , Biofuels , Butanols , Fermentation , Lignin/metabolism
19.
Chinese Journal of Biotechnology ; (12): 2478-2493, 2020.
Article in Chinese | WPRIM | ID: wpr-878504

ABSTRACT

Filamentous microalga Tribonema sp. has the advantages of highly resistance to zooplankton-predation, easy harvesting, and high cellular lipid content, in particular large amounts of palmitoleic acid (PA) and eicosapentaenoic acid (EPA). Therefore, Tribonema sp. is considered as a promising biomass feedstock to produce biodiesel and high-value products. In this work, we studied the effect of different concentrations of nitrogen (NaNO₃: 255-3 060 mg/L), phosphorus (K₂HPO₄: 4-240 mg/L), iron ((NH₄)₃FeC₁₂H₁₀O₁₄: 0.6-12 mg/L) and magnesium (MgSO₄: 7.5-450 mg/L) on the biomass, lipid content, and fatty acid composition of Tribonema sp. FACHB-1786, aiming at enhancing cell lipid productivity. The growth of Tribonema sp. had a positive correlation with the concentration of magnesium, and the maximum biomass of Tribonema sp. (under the condition of 450 mg/L MgSO₄) was 8.09 g/L, much greater than those reported in previous studies using the same and other Tribonema species under autotrophic conditions. Different nitrogen concentrations exerted no significant effect on algal growth (P > 0.05), but a higher nitrogen concentration resulted in a greater amount of lipid in the cells. The maximum volumetric productivities of total lipids (319. 6 mg/(L·d)), palmitoleic acid (135.7 mg/(L·d)), and eicosapentaenoic acid (24.2 mg/(L·d)) of Tribonema sp. were obtained when the concentrations of NaNO₃, K₂HPO₄, (NH₄)₃FeC₁₂H₁₀O₁₄, and MgSO₄ were 765 mg/L, 80 mg/L, 6 mg/L, and 75 mg/L, respectively. This study will provide a reference for substrate optimization for Tribonema sp. growth and lipid production.


Subject(s)
Biofuels , Biomass , Lipids , Microalgae , Nitrogen , Stramenopiles
20.
Chinese Journal of Biotechnology ; (12): 2126-2138, 2020.
Article in Chinese | WPRIM | ID: wpr-878472

ABSTRACT

Development of "liquid sunshine" could be a key technology to deal with the issue of fossil fuel depletion. β-caryophyllene is a terpene compound with high energy density and has attracted attention for its potential application as a jet fuel. The high temperature and high light-tolerant photosynthetic cyanobacterium Synechococcus elongatus UTEX 2973 (hereafter Synechococcus 2973), whose doubling time is as short as 1.5 h, has great potential for synthesizing β-caryophyllene using sunlight and CO₂. In this study, a production of ~121.22 μg/L β-caryophyllene was achieved at 96 h via a combined strategy of pathway construction, key enzyme optimization and precursor supply enhancement. In addition, a final production of ~212.37 μg/L at 96 h was realized in a high-density cultivation. To our knowledge, this is the highest production reported for β-caryophyllene using cyanobacterial chassis and our study provide important basis for high-density fuel synthesis in cyanobacteria.


Subject(s)
Biofuels/microbiology , Carbon Dioxide/metabolism , Light , Photosynthesis , Synechococcus/radiation effects
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