Lignocellulose Fermentation Products Generated by Giant Panda Gut Microbiomes Depend Ultimately on pH Rather than Portion of Bamboo: A Preliminary Study.

Giant pandas feed almost exclusively on bamboo but miss lignocellulose-degrading genes. Their gut microbiome may contribute to their nutrition; however, the limited access to pandas makes experimentation difficult. In vitro incubation of dung samples is used to infer gut microbiome activity.

Selecting fermentation products for food waste valorisation with HRT and OLR as the key operational parameters.

Acidogenic fermentation is attractive for food waste valorisation. A better understanding is required on how operation affects product selectivity. This study demonstrated that the hydraulic retention time (HRT) and organic loading rate (OLR) selected fermentation pathways in a single-stage, semi-continuous stirred tank reactor.

Substrate-Dependent Fermentation of Bamboo in Giant Panda Gut Microbiomes: Leaf Primarily to Ethanol and Pith to Lactate.

The giant panda is known worldwide for having successfully moved to a diet almost exclusively based on bamboo. Provided that no lignocellulose-degrading enzyme was detected in panda's genome, bamboo digestion is believed to depend on its gut microbiome. However, pandas retain the digestive system of a carnivore, with retention times of maximum 12 h.

Chemicals from Food Supply Chain By-Products and Waste Streams.

Circular economy and bioeconomy concepts have been introduced within an EU framework to sustainably overcome the dominant development model of "take, make, and dispose", which has contributed to current economic, environmental, and societal burdens [...

Medium Chain Carboxylic Acids from Complex Organic Feedstocks by Mixed Culture Fermentation.

Environmental pressures caused by population growth and consumerism require the development of resource recovery from waste, hence a circular economy approach. The production of chemicals and fuels from organic waste using mixed microbial cultures (MMC) has become promising. MMC use the synergy of bio-catalytic activities from different microorganisms to transform complex organic feedstock, such as by-products from food production and food waste.

A Group IV Species Dominates and Suppresses a Mixed Culture Fermentation by Tolerance to Medium Chain Fatty Acids Products.

A microbial community is engaged in a complex economy of cooperation and competition for carbon and energy. In engineered systems such as anaerobic digestion and fermentation, these relationships are exploited for conversion of a broad range of substrates into products, such as biogas, ethanol, and carboxylic acids. Medium chain fatty acids (MCFAs), for example, hexanoic acid, are valuable, energy dense microbial fermentation products, however, MCFA tend to exhibit microbial toxicity to a broad range of microorganisms at low concentrations.

Efficient molasses fermentation under high salinity by inocula of marine and terrestrial origin.

Background: Molasses is a dense and saline by-product of the sugar agroindustry. Its high organic content potentially fuels a myriad of renewable products of industrial interest. However, the biotechnological exploitation of molasses is mainly hampered by the high concentration of salts, an issue that is nowadays tackled through dilution.

Acetate accumulation enhances mixed culture fermentation of biomass to lactic acid.

Lactic acid is a high-in-demand chemical, which can be produced through fermentation of lignocellulosic feedstock. However, fermentation of complex substrate produces a mixture of products at efficiencies too low to justify a production process. We hypothesized that the background acetic acid concentration plays a critical role in lactic acid yield; therefore, its retention via selective extraction of lactic acid or its addition would improve overall lactic acid production and eliminate net production of acetic acid.

Product Diversity Linked to Substrate Usage in Chain Elongation by Mixed-Culture Fermentation.

Acetate and ethanol can be converted to caproic acid by microorganisms through reverse β-oxidation. There is limited insight into the versatility of chain elongation in view of different starting substrates, including even- and odd-carbon carboxylates and alcohols other than ethanol. Thermodynamic analyses show that most elongation pathways are energetically feasible.

High salinity in molasses wastewaters shifts anaerobic digestion to carboxylate production.

Biorefinery wastewaters are often treated by means of anaerobic digestion to produce biogas. Alternatively, these wastewaters can be fermented, leading to the formation of carboxylates. Here, we investigated how lab-scale upflow anaerobic sludge blanket reactors could be shifted to fermentation by changing organic loading rate, hydraulic retention time, pH, and salinity.

Electrolytic extraction drives volatile fatty acid chain elongation through lactic acid and replaces chemical pH control in thin stillage fermentation.

Background: Volatile fatty acids (VFA) are building blocks for the chemical industry. Sustainable, biological production is constrained by production and recovery costs, including the need for intensive pH correction. Membrane electrolysis has been developed as an in situ extraction technology tailored to the direct recovery of VFA from fermentation while stabilizing acidogenesis without caustic addition.

Electrolytic membrane extraction enables production of fine chemicals from biorefinery sidestreams.

Short-chain carboxylates such as acetate are easily produced through mixed culture fermentation of many biological waste streams, although routinely digested to biogas and combusted rather than harvested. We developed a pipeline to extract and upgrade short-chain carboxylates to esters via membrane electrolysis and biphasic esterification. Carboxylate-rich broths are electrolyzed in a cathodic chamber from which anions flux across an anion exchange membrane into an anodic chamber, resulting in a clean acid concentrate with neither solids nor biomass.

Granularity determination of activated sludge through on-line profiles by means of case-based reasoning.

Aerobic granulation from floccular sludge is difficult to detect in first stages with the naked eye. This work proposes a combination of multi-way principal components and case-based reasoning to predict the granulation state of a sequencing batch reactor, based solely on the on-line registered profiles of common sensors (i.e.

Optimisation of glycogen quantification in mixed microbial cultures.

This study addressed the key factors affecting the extraction and quantification of glycogen from floccular and granular mixed microbial cultures collected from activated sludge, nutrient removal systems and photosynthetic consortiums: acid concentration, hydrolysis time and concentration of biomass in the hydrolysis. Response surface modelling indicated that 0.9 M HCl and a biomass concentration of 1 mg mL(-1) were optimal conditions for performing acid hydrolysis.

Autotrophic denitrification in microbial fuel cells treating low ionic strength waters.

The presence of elevated concentrations of nitrates in drinking water has become a serious concern worldwide. The use of autotrophic denitrification in microbial fuel cells (MFCs) for waters with low ionic strengths (i.e.

Microbial fuel cell application in landfill leachate treatment.

The feasibility of using microbial fuel cells (MFCs) in landfill leachate treatment and electricity production was assessed under high levels of nitrogen concentration (6033 mg NL(-1)) and conductivity (73,588 μS cm(-1)). An air-cathode MFC was used over a period of 155 days to treat urban landfill leachate. Up to 8.

Effect of pH on nutrient dynamics and electricity production using microbial fuel cells.

The aim of this work was to study the effect of pH on electricity production and contaminant dynamics using microbial fuel cells (MFCs). To investigate these effects, an air-cathode MFC was used to treat urban wastewater by adjusting the pH between 6 and 10. The short-term tests showed that the highest power production (0.

Nitrogen removal from landfill leachate using the SBR technology.

Landfill leachate is a concern in the wastewater field due to its toxicity, high ammonium and low biodegradable organic matter concentrations. The aim of this paper is to study the reliability of landfill leachate treatment using Sequencing Batch Reactor (SBR) technology for biological nitrogen removal. During the study the SBR pilot plant treated successfully 0.