Biochemical Changes in Decomposing Leaves of Mangroves

Rajendran, Narayanasamy; Kathiresan, K.

doi:10.1080/02757540008037664

Cited by 24 publications

(17 citation statements)

References 10 publications

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“…After the gradual leaching of tannin, the counts also increased. But the fungal count was high when content of tannin was high in the initial days of decomposition, after that the count declined with lowering of tannin (Rajendran 1997, Rajendran andKathiresan 2000). This early colonization of fungi in tannin-rich mangrove leaves may be due to the fact that the fungi like Aspergilli are capable of producing tannase enzyme to degrade tannin (William et al 1986).…”

Section: Discussionmentioning

confidence: 99%

Microbial flora associated with submerged mangrove leaf litter in India

Rajendran

Kathiresan

2006

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Abstract:We studied the microbial flora in decomposing mangrove leaves in relation to changes in nitrogen and tannin levels, and in penaeid prawn assemblages. Senescent leaves of two mangrove species (Rhizophora apiculata and Avicennia marina) kept in nylon bags, were separately immersed for 80 days in five tanks full of mangrove water. A known amount of decomposing leaves was collected every ten days from each tank for microorganism counts, total nitrogen and tannin measurement, and juvenile penaeid prawn counts. Five genera of total heterotrophic bacteria (THB), three species of azotobacters and 19 species of fungi were identified. The azotobacters showed a significant peak around 40-50 days after the beginning of of decomposition, similar to the trend for total nitrogen and for prawn assemblages. Rev. Biol. Trop. 55 (2): 393-400. Epub 2007 June, 29.Key words: Rhizophora, Avicennia, litter, microbes, decomposition, Azotobacter.Microorganisms play an important ecological role in decomposing organic matter and producing protein-rich detritus that serves as food to fishes especially in detritus-based marine ecosystems like mangroves (Dickinson and Pugh 1974, Steinke 2000, Mumby et al. 2004. Fungi are particularly important in the marine environment as decomposers of dead organic substrates (Kohlmeyer and Kohlmeyer 1979). The dead organic matter and the associated microorganisms form the base of the food webs of commercially important fishes and crustaceans. The undecomposed leaves are poor in nutrients, and they become nutritious due to the microbial enrichment process during decomposition (Odum 1971). The microbial decomposition of mangrove litter, has been extensively studied (Fell and Master 1973, Meyers 1974, Fell et al. 1975, Boonruang 1978, Cundell et al. 1979, Misra et al. 1984, Robertson 1988, Raghukumar et al. 1994, Rajendran and Kathiresan 1999a, 2000, Kathiresan and Bingham 2001, Rajendran and Kathiresan 2004 especially for the prevalence of fungi in decaying seedlings (Newell 1976). The microbial activity results in mineralization of detritus and a decrease in C/N ratio (Blum et al. 1988).Although microbes play an important role in the cycling of nutrients in the mangrove ecosystem, very little information is available about the types of microbes associated with decomposing leaves. These studies have not been extended to faunal assemblages associated with the decomposing leaves, especially for juvenile penaeid prawns which are usually abundant in mangrove waters (Rajendran 1997, Rajendran and Kathiresan 1999b. Hence, the present study was made on microbial load during decomposition of two mangrove species. mangrove forest at Pichavaram (11°27' N, 79°47' E) located in southeast coast of India and shade-dried. The leaves weighing at 500 g, without dissection, were packed in five nylon bags (35 x 35 cm, 2 mm mesh size) and submerged in five tanks (1.5 x 1.0 m), which were constructed separately for Rhizophora and Avicennia in the lower intertidal areas adjacent to the mangrove forest. To facilitate the b...

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Section: Discussionmentioning

confidence: 99%

Microbial flora associated with submerged mangrove leaf litter in India

Rajendran

Kathiresan

2006

RBT

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“…Furthermore, the peaks of 18 : 1 n7 recorded in the dry season out of the Kinondo mouth are likely the result of the retention feature of the area. Indeed, a higher increase in 18 : 1 n7 than branched FAs was observed after 40 days of decomposition of Rhizophora apiculata leaves (Rajendran and Kathiresan, 2000), co-genus species of R. mucronata, the most abundant species living along the Kinondo creek.…”

Section: Contribution Of Other Primary Producers To the Sediment And mentioning

confidence: 97%

Small-scale variability in geomorphological settings influences mangrove-derived organic matter export in a tropical bay

et al. 2017

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Abstract. Organic matter (OM) exchanges between adjacent habitats affect the dynamics and functioning of coastal systems, as well as the role of the different primary producers as energy and nutrient sources in food webs. Elemental (C, N, C : N) and isotope (δ 13 C) signatures and fatty acid (FA) profiles were used to assess the influence of geomorphological setting in two climatic seasons on the export and fate of mangrove OM across a tidally influenced tropical area, Gazi Bay (Kenya). The main results indicate that tidal transport, along with riverine runoff, plays a significant role in the distribution of mangrove organic matter. In particular, a marked spatial variability in the export of organic matter from mangroves to adjacent habitats was due to the different settings of the creeks flowing into the bay. Kinondo Creek acted as a mangrove retention site, where export of mangrove material was limited to the contiguous intertidal area, while Kidogoweni Creek acted as a "flow-through" system, from which mangrove material spreads into the bay, especially in the rainy season. This pattern was evident from the isotopic signature of primary producers, which were more 13 C-depleted in the Kinondo Creek and nearby, due to the lower dilution of the dissolved inorganic carbon (DIC) pool, typically depleted as an effect of intense mangrove mineralisation. Despite the trapping efficiency of the seagrass canopy, suspended particulate OM showed the important contribution of mangroves across the whole bay, up to the coral reef, as an effect of the strong ebb tide. Overall, mixing model outcomes indicated a widespread mixed contribution of both allochthonous and autochthonous OM sources across Gazi Bay. Moreover, FAs indicated a notable contribution of brown macroalgae and bacteria in both sediment and suspended pools. These results suggest that ecological connectivity in Gazi Bay is strongly influenced by geomorphological setting, which may have far-reaching consequences for the functioning of the whole ecosystem and the local food webs.

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“…These timelines were selected because of the biotic and nutrient characteristics of the decomposing mangrove leaf litter. For instance, after 1 wk of decomposition, microbiota abundance and levels of unsaturated FAs are low (Mfilinge et al 2003, Gatune et al 2012; in the fifth week, the litter has high microbiota abundance and high levels of unsaturated FAs (Alikunhi et al 2010, Gatune et al 2012, and beyond the tenth week, the litter is characterized by a high (> 90%) loss of tannins (Rajendran & Kathiresan 2000). FA composition of the tail tissue of P. monodon PL from the different treatments was compared to the FA composition of the food.…”

Section: Shrimp Feeding Experiment: Set Up and Designmentioning

confidence: 99%