Exopolysaccharide Distribution of and Bioemulsifier Production by
            <i>Acinetobacter calcoaceticus</i>
            BD4 and BD413

Nutritional requirements for maximal production of biosurfactant by an oil field bacterium Pseudomonas putida were determined. The optimal concentrations of nitrogen, phosphate, sulfur, magnesium, iron, potassium, sodium, calcium, and trace elements for maximal production of biosurfactants were ascertained, and a new "Pruthi and Cameotra" salt medium was formulated. Data show that maximal biomass (2.4 g L −1 ) and biosurfactant production (6.28 g L −1 ) takes place after 72 h of growth on 2% hexadecane. The biosurfactant was produced optimally over pH and temperature ranges of 6.4-7.2 and 30-40°C, respectively. That the highest biosurfactant yield was obtained during late log phase of growth indicates that the biosurfactant is a secondary metabolite. FIG. 1. Effect of different concentrations of (A) nitrogen, (B) phosphorus, (C) sulfur, and (D) magnesium on growth and biosurfactant activities of Pseudomonas putida. ■, Surface tension; ◆, emulsification index; ▲, dry biomass.68

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“…1). The results also indicated that the requirement for Mg 2+ (15 ppm) is low in comparison with other biosurfactant-producing bacteria (19).…”

Section: Resultsmentioning

confidence: 79%

Effect of nutrients on optimal production of biosurfactants by Pseudomonas putida—A gujarat oil field isolate

Pruthi

Cameotra

2003

J Surfact & Detergents

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“…Aeinetobacter ealcoaceticus ATCC 14987 was obtained from the Ameriean Type Culture Collection, Rockville, MD, U.S.A. The organism was grown in minimal medium (Kaplan & Rosenberg, 1982) suppletnented with 2kg m"-' (w/v) easamino aeids (Difeo). Cells in late exponential phase of growth were harvested by eentrifugation, washed with 50 mol m"-' K phosphate (pH 7.0) eontaining 1 mol m~-^ dithiothreitol (DTT) (Buffer C) and were stored at -70°C until used.…”

Section: Bacterial Growth Extract Preparation and Enzyme Assaysmentioning

confidence: 99%

Higher plants express 3‐deoxy‐D‐manno‐octulosonate 8‐phosphate synthase

Doong

Ahmad

Jensen

1991

Plant Cell & Environment

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Abstract. The enzymatic activity of 3‐deoxy‐D‐manno‐octulosonate 8‐phosphate (KDOP) synthase was detected in eight diverse plant species, thus providing enzymological data consistent with recent reports of the presence of 3‐deoxy‐D‐manno‐octulosonate in plant cell walls. KDOP synthase from spinach was partially purified and characterized. It possessed weak activity as 3‐deoxy‐D‐arabino‐heptulosonate 7‐phosphate (DAHP) synthase. In the presence of phosphoenolpyruvate, which conferred dramatic thermostability, KDOP synthase had a catalytic temperature optimum of about 53°C. The pH optimum was 6.2, and divalent cations were neither stimulatory nor required for activity. The Km values for arabinose 5‐P and phosphoenolpyruvate were 0.27 mol m−3 and about 35 mmol m−3, respectively. The kinetics of periodate oxidation of KDOP formed by spinach KDOP synthase indicate that the same stereochemical configuration exists as with bacterial KDOP. The possibility that an unregulated species of DAHP synthase found in some bacteria might in fact be a KDOP synthase exhibiting substrate ambiguity of the type seen in higher plants was examined. However, the DAHP synthase isozyme, DS‐O, from Acinetobacter calcoaceticus was found to be specific for erythrose 4‐P. The KDOP synthase of Acinetobacter calcoaceticus was also found to be specific for arabinose 5‐P.

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“…Ac. calcoaceticus BD4 and BD413, ATCC 17294, ATCC 17906, were also investigated for emulsi®er production (Kaplan and Rosenberg 1982;Kaplan et al 1987). However, there is no report of bioemulsi®er production by Acinetobacter strains from human skin.…”

Section: Introductionmentioning

confidence: 99%

Studies on bioemulsifier production by Acinetobacter strains isolated from healthy human skin

Patil

Chopade

2001

J Appl Microbiol

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Aims: In recent years, interest has been growing in the search for novel bioemulsifiers. Many bacterial genera including Acinetobacter have been reported to produce bioemulsifiers. The present study aims to screen Acinetobacter isolates from healthy human skin for bioemulsifier production. Methods and Results: Acinetobacter junii SC14 produced maximum bioemulsifier in the presence of almond oil during stationary growth phase at 37°C and pH 7·2. Partially purified, nondialysable bioemulsifier from SC14 was a proteoglycan. The protein and polysaccharide fractions resulted in 95·2% reconstitution of the emulsification activity. The role of esterase in the release of cell‐bound emulsifier and the contribution of capsular polysaccharide to the emulsification activity were observed. Conclusion: Acinetobacter strains from human skin exhibited better emulsification activity than that by burn wound or soil isolates, owing to the inherent differences in chemical microenvironment of their habitats. Significance and Impact of the Study: Investigation of skin commensals, especially acinetobacters, would lead to the discovery of novel bioemulsifiers with interesting properties. Attempts of screening and strain improvement directed towards skin commensals will open up new avenues for strains producing bioemulsifier on a commercial scale.

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Exopolysaccharide Distribution of and Bioemulsifier Production by Acinetobacter calcoaceticus BD4 and BD413

Cited by 119 publications

References 19 publications

Effect of nutrients on optimal production of biosurfactants by Pseudomonas putida—A gujarat oil field isolate

Effect of nutrients on optimal production of biosurfactants by Pseudomonas putida—A gujarat oil field isolate

Higher plants express 3‐deoxy‐D‐manno‐octulosonate 8‐phosphate synthase

Studies on bioemulsifier production by Acinetobacter strains isolated from healthy human skin

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