Bacterial abundance and production, and their relation to primary production in tropical coastal waters of Peninsular Malaysia

Abstract

In the present study, the relationship between bacteria and phytoplankton in tropical coastal waters was investigated. The bacterial abundance, bacterial production, chlorophyll a concentration and net primary production were measured at several locations in the coastal waters of Peninsular Malaysia. Chlorophyll a concentration ranged from 0.40 to 32.81 μg L–1, whereas bacterial abundance ranged from 0.1 to 97.5 × 106 cells mL–1. Net primary production ranged from 8.49 to 55.95 μg C L–1 h–1, whereas bacterial production ranged from 0.17 to 70.66 μg C L–1 h–1. In the present study, the carbon conversion factor used to convert bacterial production (cells mL–1 h–1) into carbon units ranged from 10 to 32.8 fg C cell–1, and was estimated from the bacterial size distribution measured at each location. Both phototrophic and heterotrophic biomass (bacteria–chlorophyll a) and activity (bacterial production–net primary production) were significantly correlated, although their correlation coefficients (r2) were relatively low (r2 = 0.188 and r2 = 0.218 respectively). Linear regression analyses provided the following equations to represent the relationship between: bacteria and chlorophyll a (Chl a), log Bacteria = 0.413 log Chl a + 6.057 (P = 0.003); and between bacterial production (BP) and net primary production (NPP), log BP = 0.896 log NPP – 0.394 (P = 0.004), which fitted with published results well. Comparison of annual carbon fluxes confirmed the prevalence of net heterotrophy in these coastal waters, and together with the low correlation coefficients, suggested the role of allochthonous organic matter in supporting heterotrophic activity.

Isolation and characterization of culturable bacteria from tropical coastal waters

“…This concurs with Lee and Bong (2008) who reported high rates of primary and bacterial productivity at Klang relative to the other stations. High TSS was also observed at stations along the Straits of Malacca, and this is often attributed to land clearing activities for construction projects, mining, agricultural and forest industries, and dredging operations (Lee and Bong 2006).…”

“…High TSS was also observed at stations along the Straits of Malacca, and this is often attributed to land clearing activities for construction projects, mining, agricultural and forest industries, and dredging operations (Lee and Bong 2006). The cfu and bacterial counts obtained in this study were within the range previously reported for Malaysian waters: 100-2500 cfu mL -1 (Lee 2003) and 0.1-97.5 × 10 6 cells mL -1 (Lee and Bong 2008). The ratio of culturable bacteria to total bacteria was from 0.04% to 0.12%, which is similar to Las ufc mL -1 medidas fueron de 0.23 a 1.85 × 10 3 y menores en la estación 2 de Kuantan ( fig.…”

Temporal variation of phytoplankton growth and grazing loss in the west coast of Peninsular Malaysia

“…Surface seawater temperature observed was relatively high and stable, and is typical of tropical coastal waters (Lee and Bong 2008). Salinity was more variable at the Klang estuary due to the Klang River influx.…”

“…In the classical pathway, phytoplankton production is transferred to higher level via grazing, and subsequently affects fishery yield (Mann 1993) whereas in the microbial pathway, phytoplankton production is coupled to bacterial consumption via the 15 dissolved organic matter pool (Azam et al 1983, del Giorgio et al 1997, Cole 1999. Although the microbial pathway is relatively well-studied in the coastal waters of Peninsular Malaysia (Lee and Bong 2008, Lee et al 2009, Bong and Lee 2011, Lee and Bong 2012, the classical pathway remains poorly characterized.…”

Significant contribution of lytic mortality to bacterial production and DOC cycles in Funka Bay, Japan

“…Primary production during the spring bloom accounts for one-third of the annual production in the bay. Bacterial growth and production are stimulated just after the spring bloom or artificially induced bloom (Lee et al 2001b;Kudo et al 2009). The highest bacterial production in April seemed the result of increased DOM supply after the bloom through exudation, viral lysis or zooplankton grazing.…”