Influence of culture conditions and medium composition on the production of antibacterial compounds by marine Serratia sp. WPRA3

Abstract

This study was undertaken to investigate the influence of culture conditions and medium components on production of antibacterial compounds by Serratia sp. WPRA3 (JX020764) which was isolated from marine water of Port Dickson, Malaysia. Biochemical, morphological, and molecular characteristics suggested that the isolate is a new candidate of the Serratia sp. The isolate showed strong antimicrobial activity against fungi, Gram-negative and Gram-positive bacteria. This bacterium exhibited optimum antibacterial compounds production at 28°C, pH 7 and 200 rev/min aeration during 72 h of incubation period. Highest antibacterial activity was obtained when sodium chloride (2%), yeast extract (0.5%), and glucose concentration (0.75%) were used as salt, nitrogen, and carbon sources respectively. Different active fractions were obtained by Thin-Layer Chromatography (TLC) and Flash Column Chromatography (FCC) from ethyl acetate crude extracts namely OCE and RCE in different culture conditions, OCE (pH 5, 200 rev/min) and RCE (pH 7/without aeration). In conclusion, the results suggested different culture conditions have a significant impact on the types of secondary metabolites produced by the bacterium.

Antimicrobial Potential of Epiphytic Bacteria Associated With Seaweeds of Little Andaman, India

“…All the potential isolates were cultured in inorganic salt medium referred to as minimal medium for the extraction of secondary metabolites ( Jafarzade et al, 2013 ).…”

“…Potential cultures were cultivated in 100 ml minimal medium supplemented with 3% NaCl, 1% glucose and 1% yeast extract as carbon and nitrogen sources in a 250 ml Erlenmeyer flask and incubated at 32°C for 24 h in an incubator shaker. Five milliliter of this culture was used as bacterial (Starter) culture ( Jafarzade et al, 2013 ).…”

“…After incubation cell free supernatant was extracted three times with ethyl acetate (EtOAc). Sterile media without the inoculum adjusted with various concentration of sodium chloride was used as control ( Jafarzade et al, 2013 ). The extracts were then tested for antimicrobial activity.…”

Production, characterization and antibacterial activity of prodigiosin pigment produced by Pseudoalteromonas rubra BF1A IBRL associated with a marine macroalgae Enteromorpha sp.

“…Moreover, the crude prodigiosin pigment extract from P. rubra BF1A IBRL shows lower MIC values (55 µg/mL) against S. aureus and S. aureus (MRSA) when comparing with crude prodigiosin pigment produced by other bacteria likes Serratia sp. as reported by Jafarzade et al (2013), where the MIC values ranges from 83.3 to 200 µg/mL. Presumably, the prodigiosin pigment inhibit the test bacteria by disrupting the cell membrane.…”

“…Prodigiosin is very common in term of its inhibitory effect against wide range of bacteria including pathogens (Jafarzade et al, 2013) and fouling bacteria as well (Priya et al, 2013). Hence, the antibacterial effect from P. rubra.…”