1.Selective cytotoxicity of bioluminescent bacteria isolated from fresh ink of Philippine squid on human colon cancer and normal cell lines
Malaysian Journal of Microbiology 2017;13(3):244-252
Aims: The current work determined the cytotoxicity of the symbiont bioluminescent bacteria isolated from fresh ink of
the squid, Photololigo duvaucelii for human colon cancer cell lines HT-29 and HCT116 and normal human dermal
fibroblasts.
Methodology and results: The crude sterile culture supernatants of the bacterial isolates grown in marine broth
containing 2.8% of NaCl were tested for their cytotoxic activities for HT-29 and HCT-116 human colon cancer cells and
the normal human dermal fibroblasts HDFn using Presto Blue™ Resazurin Assay. Zeocin served as the positive control.
The cytotoxicity index profiles of all culture supernatants and negative control (marine broth with 2.8% NaCl) for HDFn
suggest non-toxicity to the cells, whereas most culture supernatants were observed to be cytotoxic to the two colon
cancer cell lines. The culture supernatants of the isolates were found to be more cytotoxic for the HT-29 colon cancer
cells than to the HCT-116 colon cancer cells. At the same time, the IC50 values showed that 85% (17/20) and 40% (8/20)
of the culture supernatants tested were significantly lower, hence more potent than zeocin for HT-29 and HCT-116,
respectively (p < 0.05). The rest were equally potent (p > 0.05). The 16S rRNA gene sequence analysis of the
bioluminescent isolates studied revealed that they have a 97-99% similarity identity with Photobacterium leiognathi.
Conclusion, significance and impact of study: This may be the first report on the cytotoxic activities on cancer cells
of P. leiognathi from the Philippine squid and suggests the potential use of the secondary metabolites of these
bioluminescent bacteria as anti-cancer agents.
2.Streptomycetes associated with marine sponges collected from Andaman Sea and its antibacterial activity
Ram Baskaran ; Subramanian Thenmozhi ; P.M. Mohan
Malaysian Journal of Microbiology 2017;13(3):253-260
Aims: Sponges harbour diverse prokaryotic and eukaryotic microbes. However, diversity of sponge-derived
Actinomycetes is of high interest because of its bioactive compounds. In the present study, diversity of Streptomycetes
associated with marine sponges collected from Pongibalu (south Andaman) was investigated.
Methodology and results: Sponges samples were collected by underwater SCUBA diver and Kuster’s agar media was
used for isolation of actinobacteria. Colony morphology and 16s rRNA were studied for identification of isolates and
phylogenetic tree was constructed using MEGA.6. A total of ten Streptomyces species were identified based on 16S
rRNA gene sequencing from three sponge species (Hemiasterella spp. Tentorium spp. and Tethyopsis spp.). The
organic extracts of these ten isolates revealed bioactivity against tow Gram positive and eight Gram negative pathogenic
bacteria.
Conclusion, significance and impact of study: This study suggests prospects and potentials of the diverse population
of Streptomyces with bioactivity in marine sponges. It would be a potential source in the pharmaceutical industries. As
well as actinobacteria associated with sponge may prevent the sponge from pathogenic bacteria, fungi, virus and other
microflora by secretion of secondary metabolites on surface and inside. To understand the sponge and actinobacteria
association and its bioactivity, a profound study need to be conducted.
3.Microbial isolation and degradation of selected haloalkanoic aliphatic acids by locally isolated bacteria: A review
Siti Nurul Fasehah Ismail ; Fahrul Huyop
Malaysian Journal of Microbiology 2017;13(3):261-272
The liberation of halogenated compounds by both natural processes and man-made activities has led to extensive
contamination of the biosphere. Bioremediation via the dehalogenation process offers a sustainable way to eliminate
such hazardous contaminants. Whereas, a large number of natural soil microorganisms (i.e., bacteria and fungi) that
have been isolated are capable of degrading and detoxifying such contaminants, information on the preferred types of
halogenated compounds that they catalyze is lacking. In this review, we discuss those microorganisms that have the
potential to perform bioremediation of such environmental contaminants. We also present a method for isolating novel
dehalogenase-producing microorganisms from cow dung.
4.Purification of methanol dehydrogenase from mouth methylotrophic bacteria of tropical region
Diana Waturangi ; Nico Marko ; Maggy Thenawidjaja Suhartono
Malaysian Journal of Microbiology 2011;7(4):226-229
Aims: Purification of methanol dehydrogenase (MDH) from methylotrophic bacteria was conducted to obtain pure enzyme for further research and industrial applications due to the enzyme’s unique activity that catalyzes oxidation of methanol as an important carbon source in methylotrophic bacteria.
Methodology and Results: The enzyme was screened from methylotrophic bacteria isolated from human mouth. Purification of this enzyme was conducted using ammonium sulphate precipitation followed by cation exchange chromatography. Two types of media were used to produce the enzymes: luria broth and standard mineral salts media (MSM). MSM produced MDH with higher specific activity than LB. Specific activity was also increased along with the purification steps. Application of ammonium sulphate increased the purity of enzyme and was more effective for the enzyme produced in LB. Using sepharose increased the enzyme activity 10 -57 folds.
Conclusion, significant and impact of this study: With this, ammonium sulphate precipitation coupled with single cation exchange chromatographic system has been proved to provide sufficient purified of methanol dehydrogenase from methylotrophic bacteria origin of human mouth with high specific activity for further application.
5.Sero prevalence of Hepatitis B virus among infertile women recruited for Assisted Reproduction Technology (ART)
Abieyuwa Patricia Osemwenkha ; Kennedy Osegua Ibadin ; Onaiwu Idahosa Enabulele ; Isaiah Ndubuisi Ibeh
Malaysian Journal of Microbiology 2011;7(4):230-232
Aim: Sexually transmissible diseases such as Hepatitis B virus (HBV) causes or induces incurable often fatal infections have been transmitted through Assisted Reproduction Technology (ART). This study is to determine the seroprevalence of HBV among infertile women recruited for intrauterine insemination (I.U.I).
Methodology and Results: A 5mL of blood was collected and serum aspirated. The detection of HBV was carried out using global one-step rapid test kit relative sensitivity of 99% and specific of 97%. Age range of infertile women was 20 – 49 years. Approximately 30 (5.9%) out of the 512 recruited women were seropositive for HBV with increase in prevalence rate among age group of (25 – 29 years) and (30 – 34 years). The rate of infection of HBV was found to be insignificant in this study using chi-square statistical analysis (p > 0.0001).
Conclusion, Significance and Impact of Study: Though the rate of the virus infection were statistically insignificant but the screening should be a continuous exercise and be carried out by all fertility center.
6.Can smoking cause melanization of Cryptococcus neoformans in vivo?
Gokulshankar Sabesan ; Ranjith Mehanderkar ; Valli Kumar ; Ranjitsingh Amirtha Jacob Abbadorai
Malaysian Journal of Microbiology 2011;7(4):233-235
Earlier studies have reported on the ability of Cryptococcus neoformans to synthesize melanin from tobacco extracts / nicotine incorporated in to the medium. However a study on the utilization of components in tobacco smoke by C. neoformans for melanin production was unreported. The present study reports on ability of C. neoformans for melanization using tobacco smoke and therefore substantiate the possible link between smoking and pathogenecity in clinical cryptococcal infections as reported by several researchers.
8.Natural and controlled fermentation of Lima bean (Phaseolus lunatus) for daddawa production
Elizabeth Oluremi Farinde ; Sumbo Henrietta Abiose ; Hezekiah Adekanmi Adeniran
Malaysian Journal of Microbiology 2017;13(2):85-91
Aims: Daddawa is a traditional fermented condiment produced from legumes in Nigeria. Lima bean is an underutilized
legume in Nigeria. Natural fermentation has been the conventional method of producing daddawa but the product has
been found to be of low quality and consistency. The present study aimed at comparing the microbial and biochemical
changes during natural and controlled fermentation of lima bean for production of daddawa.
Methodology and results: Lima bean was fermented into Daddawa naturally. It was also fermented into daddawa
using pure starter culture of Bacillus subtilis and Bacillus pumilus as single starter. The microbial and biochemical
changes during both fermentation conditions were evaluated. Lima bean fermented naturally (NF) recorded the highest
total viable count at 48 h and 72 h of fermentation respectively. Alpha amylase and protease activities increased with
fermentation, and reached their peak at 48 h in both naturally fermented lima bean and pure culture fermented lima bean
samples. Lima bean fermented with B. subtilis (FBS) recorded the highest total free amino acids at 72 h (54.45 Glycine/g
dry wt.).
Conclusion, significance and impact of study: The use of lima bean for daddawa production enhanced its utilization.
Controlled fermentation of lima bean by Bacillus species improved the biochemical properties such as α-amylase and
protease activities and free amino acids content of fermenting lima beans into daddawa.
Keywords: Daddawa; fermentation; lima bean; microbial; biochemical changes
Fermentation
;
Bioreactors
9.Inhibition of marine biofouling by aquatic Actinobacteria and coral-associated marine bacteria
Diana Elizabeth Waturangi ; Jessen Purwa Hariyanto ; Windy Lois ; Rory Anthony Hutagalung ; Jae Kwan Hwang
Malaysian Journal of Microbiology 2017;13(2):92-99
Aims: Biofouling is a common biology phenomenon occuring on ship surface. This phenomenon has become serious
threat in marine industries because of great economic loss. Tributyltin has been used to prevent biofouling, but it turned
to cause the environmental problem. Therefore, the discovery of alternative environment-friendly compound is
necessarily needed.
Methodology and results: Five Actinobacteria isolates and fourteen marine bacteria isolates were tested against the
biofilm formation of eight biofouling bacteria isolates that isolated from boat surface and the attachment of three
biofouling diatoms (Amphora, Navicula, Nitzschia). Actinobacteria CW17 supernatant showed the broad spectrum
activity against all fouling bacteria, whereas BC 11-5 supernatant was the only marine bacteria that capable to inhibit
biofilm formation of V. neocaledonicus. Moreover, three representative diatoms attachment could be inhibited by the
bioactive compounds produced by Actinobacteria and marine bacteria. CW01 supernatant showed broad spectrum and
high activity against all three representative diatoms which is very promising. Molecular identification based on 16S
rDNA gene sequence showed eight fouling bacteria isolates were biofilm-forming bacteria.
Conclusions, significance and impact of study: This research showed aquatic Actinobacteria and coral-associated
marine bacteria have the potential to prevent biofouling formation. Further studies are needed to purify and characterize
these antibiofouling compounds for environmental application.
Biofouling
;
Biofilms
10.Effect of biofertilizer on the diversity of nitrogen - fixing bacteria and total bacterial community in lowland paddy fields in Sukabumi West Java, Indonesia
Masrukhin ; Iman Rusmana ; Nisa Rachmania Mubarik
Malaysian Journal of Microbiology 2017;13(2):139-146
Aims: Some of methanotrophic bacteria and nitrous oxide (N2O) reducing bacteria have been proven able to support the
plant growth and increase productivity of paddy. However, the effect of application of the methanotrophics and N2O
reducing bacteria as a biofertilizer to indigenous nitrogen-fixing bacteria and total bacterial community are still not well
known yet. The aim of the study was to analyze the diversity of nitrogen-fixing bacteria and total bacterial communty in
lowland paddy soils.
Methodology and results: Soil samples were taken from lowland paddy fields in Pelabuhan Ratu, Sukabumi, West
Java, Indonesia. There were two treatments applied to the paddy field i.e biofertilizer-treated field (biofertilizer with 50
kg/ha NPK) and control (250 kg/ha NPK fertilizer). There were nine different nifH bands which were successfully
sequenced and most of them were identified as unculturable bacteria and three of them were closely related to
Sphingomonas sp., Magnetospirillum sp. and Ideonella dechloratans respectively. In addition, there were 20 different
16S rDNA bands which were successfully sequenced. Phylogenetic analysis of the sequence showed that there were 5
phyla of bacteria, i.e. Proteobacteria (Alphaproteobacteria and Gammaproteobacteria), Chlorofexi, Gemmatimonadetes,
Clostridia, and Bacteroidetes respectively. Alphaproteobacteria was the most dominant group in lowland paddy field.
Microbial diversities in the biofertilizer-treated field were lower than that of 100% fertilizer-treated field either based on
nifH and 16S rDNA genes.
Conclusion, significance and impact study: Biofertilizer treatment has lower microbial diversity than control, either
based on nifH and 16S rDNA genes.