Methanogenesis: Seasonal changes in human impacted regions of Ashtamudi estuary (Kerala, South India)

Reshmi, Rema; Nair, K. Deepa; Zachariah, E. J.; Vincent, Salom Gnana Thanga

doi:10.1016/j.ecss.2014.11.031

Cited by 21 publications

(6 citation statements)

References 49 publications

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“…The spatial variation of sediment temperature was statistically insigni cant along the estuary whereas the temporal variation was signi cant (p=0.001) (Table 2). Previous study by Reshmi et al (Reshmi et al 2015) in Ashtamudi estuarine sediment also points out similar results. During both sampling periods, Ashtamudi estuary exhibited brackish to marine conditions with regard to pH and salinity values (Jennerjahn et al 2008).…”

Section: Spatio-temporal Variation Of Environmental Variablessupporting

confidence: 78%

“…In case of crystalline cellulose substrate, S12 (Kollam city region) showed maximum growth in April 2016 and S9 in January 2017. The cellulolytic population of cellulolytic anaerobes were very low in Ashtamudi estuary as compared to the populations of other group of obligate anaerobes like methanogens and sulphate reducing bacteria (Reshmi et al 2015).…”

Section: Abundance and Distribution Of Cellulolytic Anaerobesmentioning

confidence: 81%

“…Based on the geography, the entire Ashtamudi estuary can be subdivided into three categories-the northeast Kallada River joining portion and nger like portion as Kallada section(S1-S5), the middle portion as open estuary having marine in uence(S6-S10) and southern tip as Kollam section (S11-S13) (Jennerjahn et al 2008). The anthropogenic pressure on the sampling stations were: S1-in uence of clay factory, S4-con uence of Kallada River and also owing pressure of direct sewage disposal from the population inhabiting in the river catchments, S8-The sediments dredged for widening or national waterways were dumped, S10-Fishing harbour and hydrocarbon discharges from the shing boats, S11-Solid waste plant of Kollam city, S12 -Presence of coir retting industries (Reshmi et al 2015).…”

Section: Study Area and Relevancementioning

confidence: 99%

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Organic Matter and Anaerobic Cellulolytic Activity in Sediments of Ashtamudi Estuary, Kerala, India

Arya

Vincent

Reshma³

et al. 2022

Wetlands

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Estuarine sediments are best suited for bioprospecting cellulose degrading microorganisms because of continuous input of cellulosic carbon from rivers and terrestrial runoff, and such sediments act as a substrate for decomposition by microbes. Sediment samples were collected from thirteen stations of Ashtamudi estuary, a tropical Ramsar site during April 2016 and January 2017 and analysed for environmental variables such as temperature, pH, electrical conductivity, oxidation-reduction potential, sulphate, total organic carbon (C org ), carbohydrate, protein, lipid and labile organic matter. Microcosm experiments were conducted in the sediment samples to compare native and substrate-induced cellulase enzyme activities in mesophilic and thermophilic conditions added with crystalline cellulose and cellobiose as substrates. Abundance of cellulolytic anaerobes in the roll tubes was higher with cellobiose than crystalline cellulose. Substrate induced enzyme activity was more than native enzyme activity [0.0012±0.0001-0.004±0.002 (April 2016) and 0.004±0.001-0.161±0.002 mg glucose h -1 (January 2017)] in the sediment samples and cellulolytic activity was more pronounced in thermophilic conditions during April 2016. Redundancy analysis indicated that salinity was the highest determining factor for explaining variations among bacterial abundance and activity during April 2016 and sediment lipid content during January 2017. The study reveals that estuarine sediments can act as a potential source of thermophilic cellulase enzyme producing bacteria, which needs to be further explored owing to their vast industrial applications.

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Section: Spatio-temporal Variation Of Environmental Variablessupporting

confidence: 78%

Section: Abundance and Distribution Of Cellulolytic Anaerobesmentioning

confidence: 81%

Section: Study Area and Relevancementioning

confidence: 99%

See 1 more Smart Citation

Organic Matter and Anaerobic Cellulolytic Activity in Sediments of Ashtamudi Estuary, Kerala, India

Arya

Vincent

Reshma³

et al. 2022

Wetlands

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“…There it leads to high organic matter accumulation, which provides the substrate for aerobic and anaerobic mineralization. Despite being unable to disentangle the individual contributions of anthropogenic stressors, Reshmi et al (2015) can demonstrate that inputs from chemical industries, coconut husk retting from coir industry, contaminations from fishing and its processing industries as well as urban sewage discharges obviously contribute to the high organic matter accumulation. In such a way seasonal variations of naturally high river inputs can aggravate the detrimental effects of anthropogenically increased organic matter inputs.…”

Section: Theme 3 E Stressors Associated Primarily With Changing Anthrmentioning

confidence: 96%

“…It is not as abundant as carbon dioxide, but its warming potential is many times higher. Reshmi et al (2015) investigated the methanogenic activity in anaerobic sediments of the estuarine Ashtamudi Lake in the southern Indian state of Kerala, which is under the influence of the densely-populated catchment of the Kallada River. They find the highest methanogenic activity during the SW monsoon in August when rainfall is very high, washing dissolved and particulate matter from the intensively used hinterland into the estuary.…”

Section: Theme 3 E Stressors Associated Primarily With Changing Anthrmentioning

confidence: 99%

Changes to processes in estuaries and coastal waters due to intense multiple pressures – An introduction and synthesis

Mitchell

Jennerjahn

Vizzini

et al. 2015

Estuarine, Coastal and Shelf Science

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Coastal acidification alters estuarine sediment nitrous oxide and methane fluxes

Mazur

Fulweiler

2023

Limnol Oceanogr Letters

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The impact of coastal acidification on sediment nitrous oxide (N2O) and methane (CH4) fluxes is largely unknown. We exposed temperate estuarine sediments to moderate (pH 7.3) and extreme (pH 6.3) acidification. Sediments were collected from two sites—one exposed to high and the other to low nitrogen loading. We demonstrate that low pH has a strong effect on greenhouse gas fluxes. The response, in terms of both magnitude and direction, was site specific. Sediments from the high nitrogen loading site exhibited increased N2O fluxes and decreased CH4 fluxes under moderate and extreme acidification. In contrast, sediments from the low nitrogen loading site exhibited decreased N2O fluxes under moderate and extreme acidification while CH4 fluxes both decreased (moderate) and increased (extreme). This study highlights the dynamic response of sediment N2O and CH4 fluxes to low pH and emphasizes the need for deeper understanding of ofcoastal acidification impacts on sediment biogeochemistry.

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Methanogenesis: Seasonal changes in human impacted regions of Ashtamudi estuary (Kerala, South India)

Cited by 21 publications

References 49 publications

Organic Matter and Anaerobic Cellulolytic Activity in Sediments of Ashtamudi Estuary, Kerala, India

Organic Matter and Anaerobic Cellulolytic Activity in Sediments of Ashtamudi Estuary, Kerala, India

Changes to processes in estuaries and coastal waters due to intense multiple pressures – An introduction and synthesis

Coastal acidification alters estuarine sediment nitrous oxide and methane fluxes

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