Increased energy demands in today’s world have led to the exploitation of fossil resources as fuel. Fossil resources are not only on the verge of extinction but also causing environmental and economic issues. Due to these reasons, scientists have started focusing their interest on other eco-friendly processes to biofuel and recently, second-generation biorefinery is gaining much more attention. In second-generation biorefinery, the main objective is the valorization of lignocellulosic biomass cost-effectively. Therefore, many scientists started different bioprocessing techniques like Consolidated Bioprocessing (CBP) to produce ethanol by using a single or plethora of microorganisms to produce ethanol in a single process. In this review, in-depth study on CBP is assessed as well as biofuel’s socio-economic value and a brief study of biorefineries. The study not only involves innovative approaches used in CBP but their effect on society and economic aspects.

In recent years, the massive influx of pelagic Sargassum spp. has generated great interest in the scientific community, highlighting the urgency of addressing the physiology and biochemical composition of these species. Until now, the presence of lignified cells in the tissue of Sargassum natans and Sargassum fluitans has not been reported. Although ‘‘lignin-like’’ compounds have been identified in green algae, the presence of true lignin in the Sargassum genus has not been confirmed. Our work is the first report of lignified cells forming the secondary cell wall in these Sargassum. This study used histological techniques applied to thick sections for identifying lignin-like tissues in Sargassum spp. The dyes as Safranin O and Toluidine have been used to differentiate lignin and cellulose in conducting tissue and to indicate the presence, absence, and distribution of these compounds in tissues. This work is the initial study of the cell wall heteropolymers structure and arrangement in Sargassum spp., providing insights into the unique cell wall architecture of these seaweeds.

Abstract:Vinasse is the dark-colored wastewater that is generated by bioethanol distilleries from feedstock molasses. The vinasse that is generated from molasses contains high amounts of pollutants, including phenolic compounds and melanoindin. The goal of this work was to study the expression of laccase genes in the Trametes hirsuta strain Bm-2, isolated in Yucatan, Mexico, in the presence of phenolic compounds, as well as its effectiveness in removing colorants from vinasse. In the presence of all phenolic compounds tested (guaiacol, ferulic acid, and vanillic acid), increased levels of laccase-encoding mRNA were observed. Transcript levels in the presence of guaiacol were 40 times higher than those in the control. The lcc1 and lcc2 genes of T. hirsuta were differentially expressed; guaiacol and vanillin induced the expression of both genes, whereas ferulic acid only induced the expression of lcc2. The discoloration of vinasse was concomitant with the increase in laccase activity. The highest value of enzyme activity (2543.7 U/mL) was obtained in 10% (v/v) vinasse, which corresponded to a 69.2% increase in discoloration. This study demonstrates the potential of the Bm-2 strain of T. hirsuta for the biodegradation of vinasse.

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 Trametes hirsuta (Bm-2) was evaluated for bioethanol production from Brosimum alicastrum 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 T. hirsuta 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.Microorganisms 2019, 7, 483 2 of 16 use bioethanol as their main source of fuel. Ethanol blends vary depending on the country, containing from as low as 5% (E5) to 100% bioethanol (E100) [4][5][6][7].The growing global demand for bioethanol requires the use of alternative sources of raw materials to complement sugar cane and cornstarch, which are the main raw materials used to produce it. Starch crops are widely used for bioethanol production because of their worldwide availability, easy conversion, and high ethanol yield. These raw materials include cereals (60%-80% starch), tubers and roots (60%-90%), legumes (25%-50%), and green and immature fruits (up to 70% starch) [2].Conventionally, ethanol production from starch consists of several stages. Starch is subjected to a gelatinization process followed by a liquefaction step where starch is converted to dextrins and smaller molecules by the action of bacterial thermostable amylases at high temperatures (95-105 • C) and pH values between 6 and 6.5. This step is followed by saccharification. The liquefied starch is cooled, pH is adjusted to 4-4.5, temperatures to 60-65 • C, and a fungal glucoamylase is added to hydrolyze the oligosaccharides to glucose. The liquefaction and saccharification stages represent about 40%-50% of the total energy used during starch-based ethanol production [8][9][10].Owing to this technical complexity and the economic implications of this approach, other biological alternatives have been investigated, such as simultaneous saccharification and fermentation (SSF) and consolidated bioprocessing (CBP). The latter is a promising strategy for effective ethanol production, since it employs only one type of microorganism that is capable of both producing the enzymes to hydrolyze the biomass and converting sugars into ethanol [11,12]. This strategy has the potential of lowering the cost and enhancing the efficie...

Bioelectrochemical technologies offer alternative ways of treating wastewater and using this process to generate electricity. However, research in this area is just beginning to consider environmental transmission of viruses present in wastewater. The viral fecal indicator coliphage MS2 (the most frequently used pathogen model) was used in this study, since it is a well-known indigenous wastewater virus. The scaled-up bioelectrochemical system had a working volume of 167 L and coliphage MS2 concentration decreased from 8000 to 285 PFU/mL. The kinetics were quantified up to 15 h, after which excessive yeast growth in the system prevented further bacteriophage determination. The logarithmic reduction value (LRV) calculated within the first three hours was 3.8. From 4 hours to 14, LRV values were from 4.1 to 4.8, and in hour 15 the LRV increased to 5.3, yielding a more than 90% reduction. Overall, results obtained indicate that the scaled-up bioelectrochemical treatment system was efficient in reducing coliphage MS2 densities and could be used as a model to explore its further applicability for the reduction of viruses or pathogens in treated effluents.