scholarly journals Chemoautotrophy at the Expense of Thiosulphate: A Supplementary Nutritional Source to the Mangrove Clam-Polymesoda Erosa

Author(s):  
TresaRemya A Thomas ◽  
Tanya Singh ◽  
Tamil S Kalaimani ◽  
Nandakumar H Khadge ◽  
Mamatha S Shivaramu ◽  
...  

Abstract Chemolithoautotrophy is a primordial process, where chemical energy converts inorganic carbon to organic. The prevalence of chemosynthesis was examined in the mangrove clam, Polymesoda erosa, and the ambient sediment at Chorao Island, Mandovi estuary, Goa. The sediment system is reducing, organically rich, high in electron donors, acceptors, and inorganic carbon. This clam thrives by immersing 75-90% of its body in sulfidic sediments. Hence, it is hypothesized that it could have an adaptive mechanism like microbially mediated utilization of reduced sulfur compound, S2O32- (model compound) coupled to inorganic carbon uptake. During spawning, maximum carbonate uptake rates of 449 and 594 nmole C g dry wt-1 h-1 were recorded in the gill and foot, respectively. Next generation sequencing revealed that Thiothrix and other sulfur oxidizers gathered from ambient sediment were present in gill, mantle and foot in the ratio 1:3:14 and 1:5:6, respectively. It is inferred that the clam and these associated bacteria could make an important contribution to chemosynthetic carbon fixation. The process could serve as an essential supplementary nutritional source especially during the physiologically feeble spawning phase. To the best of our knowledge, this is the first report of chemolithoautotrophic process in P. erosa of the family Cyrenidae.

2021 ◽  
Vol 97 (4) ◽  
Author(s):  
Beichen Wang ◽  
Jianrong Huang ◽  
Jian Yang ◽  
Hongchen Jiang ◽  
Haiyi Xiao ◽  
...  

ABSTRACT There is limited knowledge of microbial carbon fixation rate, and carbon-fixing microbial abundance and diversity in saline lakes. In this study, the inorganic carbon uptake rates and carbon-fixing microbial populations were investigated in the surface sediments of lakes with a full range of salinity from freshwater to salt saturation. The results showed that in the studied lakes light-dependent bicarbonate uptake contributed substantially (>70%) to total bicarbonate uptake, while the contribution of dark bicarbonate uptake (1.35–25.17%) cannot be ignored. The light-dependent bicarbonate uptake rates were significantly correlated with pH and turbidity, while dark bicarbonate uptake rates were significantly influenced by dissolved inorganic carbon, pH, temperature and salinity. Carbon-fixing microbial populations using the Calvin-Benson-Bassham pathway were widespread in the studied lakes, and they were dominated by the cbbL and cbbM gene types affiliated with Cyanobacteria and Proteobacteria, respectively. The cbbL and cbbM gene abundance and population structures were significantly affected by different environmental variables, with the cbbL and cbbM genes being negatively correlated with salinity and organic carbon concentration, respectively. In summary, this study improves our knowledge of the abundance, diversity and function of carbon-fixing microbial populations in the lakes with a full range of salinity.


2021 ◽  
Vol 102 (3) ◽  
Author(s):  
Akbar Dastjerdi ◽  
David J. Everest ◽  
Hannah Davies ◽  
Daniela Denk ◽  
Roland Zell

Dicistroviruses are single-stranded RNA viruses in the family Dicistroviridae. The viruses have mainly been detected in arthropods and are the cause of several devastating diseases in many of these species such as honeybees. Increasingly, dicistroviruses have also been detected in both mammalian and avian species in faeces, blood and liver, but with unconfirmed pathology. Here, we report a novel dicistrovirus detected in the intestinal content of a captive red squirrel with enteritis along with the disease history, pathology and genomic characterisation of the virus. Virus particle morphology resembled those of picornaviruses with a diameter of 28–32 nm but failed to be detected using a mammalian/avian pan viral microarray. Next-generation sequencing confirmed a dicistrovirus having a typical dicistrovirus genome organization, but with the polyprotein 1 being shorter by about 100 amino acids, compared to that of other dicistroviruses. Phylogenetic analysis of ORF1 and ORF2 sequences clustered the virus with two yet unassigned dicistroviruses detected in Gorilla gorilla and a freshwater arthropod and likely to be designated to a new genus. Our data further highlights the ever-growing diversity of dicistroviruses, but the clinical significance of the virus in mammalian species and particularly red squirrels has yet to be established.


2019 ◽  
Vol 7 (10) ◽  
pp. 412 ◽  
Author(s):  
Pingping Cai ◽  
Zhuo Ning ◽  
Ningning Zhang ◽  
Min Zhang ◽  
Caijuan Guo ◽  
...  

In petroleum-contaminated aquifers, biodegradation is always associated with various types of microbial metabolism. It can be classified as autotrophic (such as methanogenic and other carbon fixation) and heterotrophic (such as nitrate/sulfate reduction and hydrocarbon consumption) metabolism. For each metabolic type, there are several key genes encoding the reaction enzymes, which can be identified by metagenomics analysis. Based on this principle, in an abnormally low dissolved inorganic carbon (DIC) petroleum-contaminated aquifer in North China, nine groundwater samples were collected along the groundwater flow, and metagenomics analysis was used to discover biodegradation related metabolism by key genes. The major new finding is that autotrophic metabolism was revealed, and, more usefully, we attempt to explain the reasons for abnormally low DIC. The results show that the methanogenesis gene, Mcr, was undetected but more carbon fixation genes than nitrate reduction and sulfate genes were found. This suggests that there may be a considerable number of autotrophic microorganisms that cause the phenomenon of low concentration of dissolved inorganic carbon in contaminated areas. The metagenomics data also revealed that most heterotrophic, sulfate, and nitrate reduction genes in the aquifer were assimilatory sulfate and dissimilatory nitrate reduction genes. Although there was limited dissolved oxygen, aerobic degrading genes AlkB and Cdo were more abundant than anaerobic degrading genes AssA and BssA. The metagenomics information can enrich our microorganic knowledge about petroleum-contaminated aquifers and provide basic data for further bioremediation.


2020 ◽  
Vol 86 (7) ◽  
Author(s):  
Laurey Steinke ◽  
Gordon W. Slysz ◽  
Mary S. Lipton ◽  
Christian Klatt ◽  
James J. Moran ◽  
...  

ABSTRACT The upper green layer of the chlorophototrophic microbial mats associated with the alkaline siliceous hot springs of Yellowstone National Park consists of oxygenic cyanobacteria (Synechococcus spp.), anoxygenic Roseiflexus spp., and several other anoxygenic chlorophototrophs. Synechococcus spp. are believed to be the main fixers of inorganic carbon (Ci), but some evidence suggests that Roseiflexus spp. also contribute to inorganic carbon fixation during low-light, anoxic morning periods. Contributions of other phototrophic taxa have not been investigated. In order to follow the pathway of Ci incorporation into different taxa, mat samples were incubated with [13C]bicarbonate for 3 h during the early-morning, low-light anoxic period. Extracted proteins were treated with trypsin and analyzed by mass spectrometry, leading to peptide identifications and peptide isotopic profile signatures containing evidence of 13C label incorporation. A total of 25,483 peptides, corresponding to 7,221 proteins, were identified from spectral features and associated with mat taxa by comparison to metagenomic assembly sequences. A total of 1,417 peptides, derived from 720 proteins, were detectably labeled with 13C. Most 13C-labeled peptides were derived from proteins of Synechococcus spp. and Roseiflexus spp. Chaperones and proteins of carbohydrate metabolism were most abundantly labeled. Proteins involved in photosynthesis, Ci fixation, and N2 fixation were also labeled in Synechococcus spp. Importantly, most proteins of the 3-hydroxypropionate bi-cycle for Ci fixation in Roseiflexus spp. were labeled, establishing that members of this taxocene contribute to Ci fixation. Other taxa showed much lower [13C]bicarbonate incorporation. IMPORTANCE Yellowstone hot spring mats have been studied as natural models for understanding microbial community ecology and as modern analogs of stromatolites, the earliest community fossils on Earth. Stable-isotope probing of proteins (Pro-SIP) permitted short-term interrogation of the taxa that are involved in the important process of light-driven Ci fixation in this highly active community and will be useful in linking other metabolic processes to mat taxa. Here, evidence is presented that Roseiflexus spp., which use the 3-hydroxypropionate bi-cycle, are active in Ci fixation. Because this pathway imparts a lower degree of selection of isotopically heavy Ci than does the Calvin-Benson-Bassham cycle, the results suggest a mechanism to explain why the natural abundance of 13C in mat biomass is greater than expected if only the latter pathway were involved. Understanding how mat community members influence the 13C/12C ratios of mat biomass will help geochemists interpret the 13C/12C ratios of organic carbon in the fossil record.


2020 ◽  
Vol 110 (4) ◽  
pp. 423-437 ◽  
Author(s):  
Muhammad Fahim Raza ◽  
Zhichao Yao ◽  
Shuai Bai ◽  
Zhaohui Cai ◽  
Hongyu Zhang

AbstractThe family Tephritidae (order: Diptera), commonly known as fruit flies, comprises a widely distributed group of agricultural pests. The tephritid pests infest multiple species of fruits and vegetables, resulting in huge crop losses. Here, we summarize the composition and diversity of tephritid gut-associated bacteria communities and host intrinsic and environmental factors that influence the microbiome structures. Diverse members of Enterobacteriaceae, most commonly Klebsiella and Enterobacter bacteria, are prevalent in fruit flies guts. Roles played by gut bacteria in host nutrition, development, physiology and resistance to insecticides and pathogens are also addressed. This review provides an overview of fruit fly microbiome structure and points to diverse roles that it can play in fly physiology and survival. It also considers potential use of this knowledge for the control of economically important fruit flies, including the sterile insect technique and cue-lure baiting.


2016 ◽  
Vol 2016 ◽  
pp. 1-4
Author(s):  
Radoslava Vazharova ◽  
Svetlana Vragaleva ◽  
Violeta Dimitrova ◽  
Samuil Ivanov ◽  
Lubomir Balabanski ◽  
...  

Congenital anomalies affect 1% to 2% of the newborns. The urinary tract and the kidneys are involved in 4-5% of the cases while upper-extremities abnormalities are present in 10%. Certain anomalies occur in isolation, whereas others are associated with systemic conditions. The prenatal detection of fetal anomalies compatible with life is a challenge for both the parents and the physician. The prognosis for the fetus/newborn and the reproductive decisions of the family largely depend on the causes underlying the disease. The reported case is of a G2P1 pregnant woman referred for routine ultrasound scan at 24 weeks of gestation (w.g.). The fetus had growth retardation, right kidney agenesis, bilateral absence of radial bones and thumbs, radial deviation of the wrists, and short humeri. Nuchal fold thickness was 5 mm and there was a single umbilical artery. After termination of pregnancy, SNP array genotyping and next-generation sequencing of targeted candidate-genes were performed trying to clarify the etiology of the fetal polymalformative syndrome. A new hypomorphic mutation inFANCD2gene was found to underlie this fetal anomaly. The case illustrates that patients/families affected by rare monogenic disorders may benefit from application of modern technologies like microarrays and NGS.


Genes ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 181
Author(s):  
Zhenya Li ◽  
Xinxin Li ◽  
Nan Song ◽  
Huiji Tang ◽  
Xinming Yin

Carabidae are one of the most species-rich families of beetles, comprising more than 40,000 described species worldwide. Forty-three complete or partial mitochondrial genomes (mitogenomes) from this family have been published in GenBank to date. In this study, we sequenced a nearly complete mitogenome of Amara aulica (Carabidae), using a next-generation sequencing method. This mitogenome was 16,646 bp in length, which encoded the typical 13 mitochondrial protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a putative control region. Combining with the published mitogenomes of Carabidae and five outgroup species from Trachypachidae, Gyrinidae and Dytiscidae, we performed phylogenetic estimates under maximum likelihood and Bayesian inference criteria to investigate the phylogenetic relationships of carabid beetles. The results showed that the family Carabidae was a non-monophyletic assemblage. The subfamilies Cicindelinae, Elaphrinae, Carabinae, Trechinae and Harpalinae were recovered as monophyletic groups. Moreover, the clade (Trechinae + (Brachininae + Harpalinae)) was consistently recovered in all analyses.


2016 ◽  
Vol 95 (13) ◽  
pp. 1457-1463 ◽  
Author(s):  
M.K. Prasad ◽  
S. Laouina ◽  
M. El Alloussi ◽  
H. Dollfus ◽  
A. Bloch-Zupan

Amelogenesis imperfecta (AI) is a clinically and genetically heterogeneous group of diseases characterized by enamel defects. The authors have identified a large consanguineous Moroccan family segregating different clinical subtypes of hypoplastic and hypomineralized AI in different individuals within the family. Using targeted next-generation sequencing, the authors identified a novel heterozygous nonsense mutation in COL17A1 (c.1873C>T, p.R625*) segregating with hypoplastic AI and a novel homozygous 8-bp deletion in C4orf26 (c.39_46del, p.Cys14Glyfs*18) segregating with hypomineralized-hypoplastic AI in this family. This study highlights the phenotypic and genotypic heterogeneity of AI that can exist even within a single consanguineous family. Furthermore, the identification of novel mutations in COL17A1 and C4orf26 and their correlation with distinct AI phenotypes can contribute to a better understanding of the pathophysiology of AI and the contribution of these genes to amelogenesis.


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