Draft genome of strain AK152, a novel thermophilic and anaerobic bacterium isolated from a hot spring in Iceland.

We present the draft genome of the bacterium strain AK152, a thermophilic, endospore-spore-forming, anaerobe isolated from a hot spring in Grensdalur, in Southwestern Iceland. This assembled genome will lay the foundation for identifying the carboxylic and amino acid fermentation pathways, suggesting biotechnological applications for this strain.

Biotechnological Prospects of AK15: End-Product Formation from Carbohydrates, Amino Acids, and Lignocellulosic and Macroalgae Hydrolysates.

The conversion of lignocellulosic and algal biomass by thermophilic bacteria has been an area of active investigation. species have proven to be particularly capable in the production of bioethanol and biohydrogen from lignocellulosic biomass, although detailed studies of their abilities to utilize the full gamut of carbohydrate, amino acids, and proteins encountered in biomass hydrolysates are seldom comprehensively examined. Here, we re-evaluate the ability of strain AK15, a highly ethanologenic strain previously isolated from a hot spring in Iceland.

Dataset describing the amino acid catabolism of .

The dataset depicts the catabolism of branched-chain amino acids by in the presence of thiosulfate under different culture conditions. The results reveal that the strain can degrade all three branched-chain amino acids resulting in the production of their corresponding branched-chain fatty acids and branched-chain alcohols with the fatty acids always being the dominant product. The highest amounts of 2-methyl-1-butanol from isoleucine were at pH 6.

Dataset describing the influence of culture conditions on the bioreduction of organic acids to alcohols by .

The dataset describes the influence of culture conditions on the bioreduction of organic acids by as reported in [1]. The data shows that during glucose fermentation of the reducing equivalents are not only converted to ethanol and hydrogen but also, in the presence of carboxylic acids (C2-C6), to its corresponding alcohol. To maximize the alcohol production produced from their carboxylic acid, several experiments were performed to investigate the effect of various environmental factors (initial glucose concentration, pH, liquid-gas phase ratio, and inhibitory effects of alcohols) on growth.

Metabolic engineering of Thermoanaerobacterium AK17 for increased ethanol production in seaweed hydrolysate.

Sustainably produced renewable biomass has the potential to replace fossil-based feedstocks, for generation of biobased fuels and chemicals of industrial interest, in biorefineries. In this context, seaweeds contain a large fraction of carbohydrates that are a promising source for enzymatic and/or microbial biorefinery conversions. The thermoanaerobe Thermoanaerobacterium AK17 is a versatile fermentative bacterium producing ethanol, acetate and lactate from various sugars.

Influence of Culture Conditions on the Bioreduction of Organic Acids to Alcohols by .

species have recently been observed to reduce carboxylic acids to their corresponding alcohols. The present investigation shows that converts C2-C6 short-chain fatty acids (SCFAs) to their corresponding alcohols in the presence of glucose. The conversion yields varied from 21% of 3-methyl-1-butyrate to 57.

Biotransformation of Carboxylic Acids to Alcohols: Characterization of Strain AK152 and 1-Propanol Production via Propionate Reduction.

strains have recently gained interest because of their ability to convert short chain fatty acids to alcohols using actively growing cells. strain AK152 was physiologically investigated for its ethanol and other alcohol formation. The temperature and pH optimum of the strain was 70 °C and pH 7.

Branched-chain amino acid catabolism of Thermoanaerobacter pseudoethanolicus reveals potential route to branched-chain alcohol formation.

The fermentation of branched-chain amino acids (BCAAs) to branched-chain fatty acids (BCFAs) and branched-chain alcohols (BCOHs) is described using Thermoanaerobacter pseudoethanolicus. BCAAs were not degraded without an electron scavenging system but were degraded to a mixture of their BCFA (major) and BCOH (minor) when thiosulfate was added to the culture. Various environmental parameters were investigated using isoleucine as the substrate which ultimately demonstrated that at higher liquid-gas phase ratios the formation of 2-methyl-1-butanol from isoleucine achieved a maximal titer of 3.

Branched-chain amino acid catabolism of Thermoanaerobacter strain AK85 and the influence of culture conditions on branched-chain alcohol formation.

The bioprocessing of amino acids to branched-chain fatty acids and alcohols is described using Thermoanaerobacter strain AK85. The amino acid utilization profile was evaluated without an electron scavenger, with thiosulfate, and in a co-culture with a methanogen. There was an emphasis on the production of branched-chain alcohols and fatty acids from the branched-chain amino acids, particularly the influence of culture conditions which was investigated using isoleucine, which revealed that the concentration of thiosulfate was of great importance for the branched-chain alcohols/fatty acid ratio produced.

Dataset describing the amino acid catabolism of strain AK85: The influence of culture conditions on end product formation.

The dataset describes the catabolism of the 20 proteogenics amino acids and their end products by strain AK85 under different electron scavenging conditions with an emphasis on the branched-chain amino acids as reported in Scully and Orlygsson, 2019.

Biotransformation of organic acids to their corresponding alcohols by Thermoanaerobacter pseudoethanolicus.

Higher order alcohols, such as 1-butanol and 1-hexanol, have a large number of applications but are currently prepared from non-renewable feedstocks. Here, the ability of Thermoanaerobacter pseudoethanolicus to reduce short-chain fatty acids to their corresponding alcohols using reducing potential generated by glucose catabolism with yields between 21.0 and 61.

Dataset describing ethanol and 1,2-propanediol production by a stenothermal moderately thermophilic anaerobe, strain AK1.

The dataset details the fermentation of D-glucose, L-rhamnose, and L-fucose and their end-product formation by the moderate thermophile strain AK1 (DSM 18778) as related to the work described in "Propanediol from L-rhamnose using the moderately thermophilic strain AK1" [1]. The influence of culture conditions on end product formation from D-glucose and L-rhamnose by AK1 was investigated in batch culture. Strain AK1 was cultivated at initial substrate concentrations varying from 0 to 60 mM and initial pH values varying from 4.

Fermentation of Mannitol Extracts From Brown Macro Algae by Thermophilic .

Mannitol-containing macro algae biomass, such as and , are a potential feedstock for the production of biofuels such as bioethanol. The purpose of this work was to evaluate the ability of thermophilic anaerobes within Class to ferment mannitol and mannitol-containing algal extracts. Screening of the type strains of six genera, , and ) was conducted on 20 mM mannitol and revealed that 11 of 41 strains could utilize mannitol with ethanol being the dominant end-product.

Production of (S)-1,2-propanediol from l-rhamnose using the moderately thermophilic Clostridium strain AK1.

Clostridium strain AK1 was investigated for its capacity of producing 1,2-propanediol from l-rhamnose but not l-fucose. The maximum yields of 1,2-propanediol from rhamnose was 0.81 mol 1,2-PD/mol l-rhamnose.

Evaluation of the genus of Caldicellulosiruptor for production of 1,2-propanediol from methylpentoses.

Caldicellulosiruptor species degrade l-rhamnose and l-fucose to 1,2-propanediol. Six of the nine species within the genus produced 1,2-propanediol from l-rhamnose and three utilized l-fucose to produce the compound. Yields of 1,2-propanediol up to 40.

Amino Acid Metabolism of Thermoanaerobacter Strain AK90: The Role of Electron-Scavenging Systems in End Product Formation.

The catabolism of the 20 amino acids by Thermoanaerobacter strain AK90 (KR007667) was investigated under three different conditions: as single amino acids without an electron-scavenging system, in the presence of thiosulfate, and in coculture with a hydrogenotrophic methanogen. The strain degraded only serine without an alternative electron acceptor but degraded 11 amino acids (alanine, cysteine, isoleucine, leucine, lysine, methionine, phenylalanine, serine, threonine, tyrosine, and valine) under both of the electron-scavenging systems investigated. Acetate was the dominant end product from alanine, cysteine, lysine, serine, and threonine under electron-scavenging conditions.

Branched-chain alcohol formation by thermophilic bacteria within the genera of Thermoanaerobacter and Caldanaerobacter.

Fifty-six thermophilic strains including members of Caldanaerobacter, Caldicellulosiruptor, Caloramator, Clostridium, Thermoanaerobacter, and Thermoanaerobacterium, were investigated for branched-chain amino acid degradation in the presence of thiosulfate in batch culture. All of the Thermoanaerobacter and Caldanaerobacter strains (24) degraded the branched-chain amino acids (leucine, isoleucine, and valine) to a mixture of their corresponding branched-chain fatty acids and branched-chain alcohols. Only one Caloramator strain degraded the branched-chain amino acids to the corresponding branched-chain fatty acids.

Branched-chain alcohol formation from branched-chain amino acids by Thermoanaerobacter brockii and Thermoanaerobacter yonseiensis.

Thermoanaerobacter species degrade branched-chain amino acids to a mixture of their corresponding branched-chain fatty acids and alcohols in the presence of thiosulfate; only acid formation occurred when Thermoanaerobacter strains were cultivated in co-culture with a hydrogenotrophic methanogen. Increased pH2 at high liquid-gas phase ratios increases the relative concentration of branched-chain alcohol.

Production of ethanol from sugars and lignocellulosic biomass by Thermoanaerobacter J1 isolated from a hot spring in Iceland.

Thermophilic bacteria have gained increased attention as candidates for bioethanol production from lignocellulosic biomass. This study investigated ethanol production by Thermoanaerobacter strain J1 from hydrolysates made from lignocellulosic biomass in batch cultures. The effect of increased initial glucose concentration and the partial pressure of hydrogen on end product formation were examined.

Effect of various factors on ethanol yields from lignocellulosic biomass by Thermoanaerobacterium AK₁₇.

The ethanol production capacity from sugars and lignocellulosic biomass hydrolysates (HL) by Thermoanaerobacterium strain AK(17) was studied in batch cultures. The strain converts various carbohydrates to, acetate, ethanol, hydrogen, and carbon dioxide. Ethanol yields on glucose and xylose were 1.

Hydrogenophilus islandicus sp. nov., a thermophilic hydrogen-oxidizing bacterium isolated from an Icelandic hot spring.

A novel chemolithotrophic bacterium, strain 16C(T), was isolated from a hot spring in Graendalur, south-west Iceland. Cells of this organism were Gram-negative, rod-shaped and motile. The isolate was aerobic and capable of chemolithotrophic growth on hydrogen and carbon dioxide, heterotrophic growth on butyrate and several other organic compounds, and mixotrophic growth on butyrate, hydrogen and carbon dioxide.

Thiomonas islandica sp. nov., a moderately thermophilic, hydrogen- and sulfur-oxidizing betaproteobacterium isolated from a hot spring.

A novel, hydrogen- and sulfur-oxidizing bacterium, designated strain 6C(T), was isolated from a hot spring in Graendalur, south-western Iceland. Cells of this organism were Gram-reaction-negative, rod-shaped and motile. The strain grew aerobically and was capable of chemolithotrophic growth on thiosulfate and hydrogen, heterotrophic growth on pyruvate, oxalate, acetate and on glutamate in the presence of yeast extract and mixotrophic growth on several organic compounds, thiosulfate and/or hydrogen.

High-efficiency hydrogen production by an anaerobic, thermophilic enrichment culture from an Icelandic hot spring.

Dark fermentative hydrogen production from glucose by a thermophilic culture (33HL), enriched from an Icelandic hot spring sediment sample, was studied in two continuous-flow, completely stirred tank reactors (CSTR1, CSTR2) and in one semi-continuous, anaerobic sequencing batch reactor (ASBR) at 58 degrees C. The 33HL produced H2 yield (HY) of up to 3.2 mol-H2/mol-glucose along with acetate in batch assay.

Ethanol and hydrogen production by two thermophilic, anaerobic bacteria isolated from Icelandic geothermal areas.

Microbial fermentations are potential producers of sustainable energy carriers. In this study, ethanol and hydrogen production was studied by two thermophilic bacteria (strain AK15 and AK17) isolated from geothermal springs in Iceland. Strain AK15 was affiliated with Clostridium uzonii (98.