On the Origin of Heterotrophy.

On the Origin of Heterotrophy. Trends Microbiol. 2015 Nov 12; Authors: Schönheit P, Buckel W, Martin WF Abstract The theory of autotrophic origins of life posits that the first cells on Earth satisfied their carbon needs from CO2. At hydrothermal vents, spontaneous synthesis of methane via serpentinization links an energy metabolic reaction with a geochemical homologue. If the first cells were autotrophs, how did the first heterotrophs arise, and what was their substrate? We propose that cell mass roughly similar to the composition of Escherichia coli was the substrate for the first chemoorganoheterotrophs. Amino acid fermentations, pathways typical of anaerobic clostridia and common among anaerobic archaea, in addition to clostridial type purine fermentations, might have been the first forms of heterotrophic carbon and energy metabolism. Ribose was probably the first abundant sugar, and the archaeal type III RubisCO pathway of nucleoside monophosphate conversion to 3-phosphoglycerate might be a relic of ancient heterotrophy. Participation of chemiosmotic coupling and flavin-based electron bifurcation - a soluble energy coupling process - in clostridial amino acid and purine fermentations is consistent with an autotrophic origin of both metabolism and heterotrophy, as is the involvement of S(0) as an electron acceptor in the facilitated fermentations of anaerobic heterotrophic archaea. PMID: 26578093 [PubMed - as supplied by publisher]
Source: Trends in Microbiology - Category: Microbiology Authors: Tags: Trends Microbiol Source Type: research

Related Links:

Publication date: Available online 1 June 2020Source: Microbial PathogenesisAuthor(s): Weiyu Wang, Menglu Cai, Junying Hu, Zecai Zhang, Xu Wang, Xiaoran Chang, Fan Zhang, Changming Guo, Xinping Wang
Source: Microbial Pathogenesis - Category: Infectious Diseases Source Type: research
The well-known fact that avian pathogenic Escherichia coli (APEC) is harder to prevent due to its numerous serogroups has promoted the development of biological immunostimulatory materials as new vaccine candidat...
Source: Microbial Cell Factories - Category: Microbiology Authors: Tags: Research Source Type: research
Publication date: Available online 2 June 2020Source: Food ChemistryAuthor(s): Zonghan Wang, Xiaolin Yao, Yongzhi Zhang, Rong Wang, Yanwei Ji, Jing Sun, Daohong Zhang, Jianlong Wang
Source: Food Chemistry - Category: Food Science Source Type: research
We report herein that EspM4VN was stable from 10°C to 50°C and pH 4 to 10 but deactivated at 70°C and pH 3 and 12. This phage formed clear plaques only on Enterobacter sp. M4 among tested bacterial strains. A one-step growth curve showed that the latent phase was 20 min, rise period was 10 min, and an average of 122 phage particles were released from each absorbed cell. We found the phage’s genome size was 160,766 bp and that it annotated 219 open reading frames. The genome organization of EspM4VN has high similarity with the Salmonella phage SKML-39; Dickeya phages Coodle, PP35, JA15, and Limestone; and ...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
An alkaline protease gene of Bacillus lehensis JO-26 from saline desert, Little Rann of Kutch, was cloned and expressed in Escherichia coli BL21 (DE3). A 1,014-bp ORF encoded 337 amino acids. The recombinant protease (APrBL) with Asp 97, His 127, and Ser 280 forming catalytic triad belongs to the subtilase S8 protease family. The gene was optimally expressed in soluble fraction with 0.2 mM isopropyl β-D-thiogalactopyranoside (IPTG), 2% (w/v) NaCl at 28°C. APrBL, a monomer with a molecular mass of 34.6 kDa was active over pH 8–11 and 30°C−70°C, optimally at pH 10 and 50°C. The enzyme was hig...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
The acid tolerance mechanism is important for Escherichia coli to resist acidic conditions encountered in mammalian host digestive tract environment. Here, we explored how the LuxR protein SdiA influenced E. coli acid tolerance ability in the context of the glutamate- and glutamine-dependent acid resistance system (AR2). First, using a growth and acid shock assay under different acid stresses, we demonstrated that the deletion of sdiA in SM10λpir or BW25113 led to impaired growth under the acidic environment of pH 3–6, which was restored by complementary expression of SdiA. Next, transcriptome sequencing and q...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
This study demonstrated high resolution and repeatability in detecting organisms of rare existence, and the results could be used as guidance for future bacterial pathogen isolation.
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
mRNA levels result from an equilibrium between transcription and degradation. Ribonucleases (RNases) facilitate the turnover of mRNA, which is an important way of controlling gene expression, allowing the cells to adjust transcript levels to a changing environment. In contrast to the heterotrophic model bacteria Escherichia coli and Bacillus subtilis, RNA decay has not been studied in detail in cyanobacteria. Synechocystis sp. PCC6803 encodes orthologs of both E. coli and B. subtilis RNases, including RNase E and RNase J, respectively. We show that in vitro Sy RNases E and J have an endonucleolytic cleavage specificity tha...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
In conclusion, bacteria associated with non-chronic or chronic wounds could function as bioindicators of healing or non-healing (chronicity), respectively. Moreover, a better understanding of bacterial interactions between pathogenic and beneficial bacteria within an evolving chronic wound microbiota may lead to better solutions for chronic wound management.
Source: Frontiers in cellular and infection microbiology - Category: Microbiology Source Type: research
Enteroinvasive Escherichia coli (EIEC) cause intestinal illness through the same pathogenic mechanism used by Shigella spp. The latter species can be typed through genomic and phenotypic methods used for E. coli and have been proposed for reclassification within E. coli species. Recently the first appearance of a highly pathogenic EIEC O96:H19 was described in Europe as the causative agent of two large outbreaks that occurred in Italy and in the United Kingdom. In contrast to Shigella spp and to the majority of EIEC strains, EIEC O96:H19 fermented lactose, lacked pathoadaptive mutations, and showed good fitness in extracel...
Source: Frontiers in cellular and infection microbiology - Category: Microbiology Source Type: research
More News: Chemistry | Gastroenteritis | Microbiology