Science Heritage Journal | Galeri Warisan Sains (GWS)

Isolation And Identification Of Halophilic Bacteria Producing Halotolerant Protease

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gws.01.2017.07.09

ABSTRACT

 

Isolation And Identification Of Halophilic Bacteria Producing Halotolerant Protease

Journal: Science Heritage Journal | Galeri Warisan Sains (GWS)
Author: Nadiah Syuhada Abd Samad, Azura Amid, Dzun Noraini Jimat and Nurul Aqilah Ab. Shukor

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Doi: 10.26480/gws.01.2017.07.09

Halotolerant proteases are known as one of the important groups of enzymes that have been used widely in various industries. However, high production cost of proteases in term of energy used for sterilization and high risk of microbial contamination during fermentation become the obstacles during upstream processing. Moreover, proteases that capable to withstand with harsh conditions of salinity, temperature and pH are required in industry. Therefore, this study presents newly isolated halophilic bacteria producing halotolerant proteases. Halophilic bacteria were isolated from fermented fish sauce. Screening of the bacteria producing halotolerant protease enzymes was carried out by using skim milk salt agar containing 10% NaCl at pH 7 and incubated under aerobic condition at 37oC for 2 days. The selected isolates were identified based on their morphology followed by 16S rDNA gene sequence analysis. 40 colonies of halophiles bacteria were isolated, however, only 20 of them showing proteolytic activity. All of 20 isolates are motile and gram positive bacteria. From 20 isolates, only 6 were chosen for further analysis. B7 showed the highest proteolytic activity compared with others. Results of 16S rDNA gene sequence analysis showed 98% homology to Bacillus amyloliquefaciens subsp. plantarum strain FZB42. Therefore, B7 is identified as Bacillus amyloliquefaciens strain B7.

Pages 07-09
Year 2017
Issue 1
Volume 1

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gws.01.2017.04.06

ABSTRACT

 

In Silico Binding Interactions Of Dehalogenase (Dehe) With Various Haloalkanoic Acids

Journal: Science Heritage Journal | Galeri Warisan Sains (GWS)
Author: Nur Illani Abd Halin, Fahrul Huyop, Tengku Haziyamin Tengku Abdul Hamid, Khairul Bariyyah Abdul Halim, Azzmer Azzar Abdul Hamid

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Doi: 10.26480/gws.01.2017.04.06

Synthetic haloalkanoic acid (HA) is one of the synthetics compounds that can be found as active ingredients in herbicides. These compounds are known to pollute our agriculture land due to their toxicity, thus may cause serious environmental and health problems. Biological process such as microbial dehalogenation degrades the harmful compounds and prevents their migration into groundwater source. For instance, Rhizobial Dehalogenase E (DehE) could catalyze these HA compounds and convert them into hydroxylated compounds which are less harmful to the environment. In previous study, DehE was considered to degrade many HA compounds with different Km values. However, the binding interaction of this enzyme towards many HA substrates is still unclear. In this study, docking simulation has been performed to determine the affinity of active site residues of DehE towards 15 HA compounds. Tribromoacetic acid (TBA) was identified to be the most favourable substrate for DehE which has the lowest binding energy (-6.48 Kcal/mol) compared to other haloalkanoic acids. Size of halogen and hydrogen bond numbers are the contributing factor for dehalogenase affinity towards its substrates. Besides, it was found that Trp34, Phe37 and Ser188 served as binding residues and Phe37 was mostly interacted and bound with all of the tested HA compounds. This findings provides an opportunity for rational design of haloacid dehalogenase especially to DehE.

Pages 04-06
Year 2017
Issue 1
Volume 1

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gws.01.2017.01.03

ABSTRACT

 

Identification Of Potential Indigenous Microbe From Local Fermented Vegetables With Antimicrobial Activity

Journal: Science Heritage Journal | Galeri Warisan Sains (GWS)
Author: Sukirah Abdul Rahman, Ainaa Abdul Kahar, Azlina Mansor, Dang Lela Murni, Aminuddin Hussin, Shaiful Adzni Sharifudin, Tan Geok Hun, Nur Yuhasliza Abdul Rashid, Muhammad Anas Othaman & Kamariah Long

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Doi: 10.26480/gws.01.2017.01.03

The objectives of this study were to identify and determine the antimicrobial activity of the indigenous microbes isolated from local fermented vegetables. Ninety nine isolates were obtained from fifteen samples of local fermented vegetables including jeruk lobak putih (pickled radish), jeruk lobak (pickled carrot), jeruk petai (pickled bitter bean), jeruk sawi sie park choy (pickled mustard), jeruk rebung (pickled bamboo shoot), jeruk maman (pickled maman), jeruk bawang putih (pickled garlic) and jeruk kobis (pickled cabbage). The antagonistic act of the isolates was assayed using well diffusion assay against five common pathogens namely, Bacillus cereus, Escherichia coli, Listeria monocytogens, Salmonella typhi and Staphylococcus aureus. Fifty three isolates showed inhibitory zones in the range of 10-18 mm under well diffusion assay. B. cereus was inhibited predominantly by the isolates (62 isolates) followed by L…monocytogens (58 isolates), E.coli (57 isolates), S.typhi (51 isolates) and S.aureus (44 isolates). A total of 19 potential isolates exhibited strong antimicrobial activity (≥10 mm) and inhibited more than two types of pathogens were selected and identified by16sRNA sequencing. Lactobacillus plantarum genera, dominates the local fermented vegetable product with 14 isolates followed by Lactobacillus brevis (3 isolates) and Pediococcus pentosaceus (2 isolates). It was acknowledge that fermented vegetable are high in salt and strongly acidic however some lactic acid bacteria are capable to withstand such growth conditions and showed antagonistic activity towards pathogens. This is a positive remark that these strains are promising candidates for development of a starter culture and to further study their potential as probiotics.

Pages 01-03
Year 2017
Issue 1
Volume 1

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Posted by Nurul