1.In vitro antimicrobial activities of methanolic extract from marine alga Enteromorpha intestinalis
Asian Pacific Journal of Tropical Biomedicine 2015;(9):753-756
To extract the bioactive compound from Enteromorpha intestinalis (E. intestinalis) and determine its in vitro antimicrobial activity. Methods: E. intestinalis was extracted by methanol and subjected to antimicrobial screening. The antimicrobial activity was studied by using disc diffusion and broth dilution method. The effect of the extract on the growth profile of the bacterial was also examined via time-kill assay. Microscopy observations using SEM was done to determine the major alterations in the microstructure of methicillin-resistant Staphylococcus aureus (MRSA). Results: The results showed methanolic extract of E. intestinalis exhibited a favourable antimicrobial activity against tested bacteria with produced inhibition zone ranging from 8.0-19.0 mm. However, all the tested fungi and yeast were resistant to the extract treatment. Time kill assay suggested that methanolic extract of E. intestinalis had completely inhibited MRSA growth and also exhibited prolonged antibacterial activity. The main abnormalities noted from the microscopic observations were the structural deterioration in the normal morphology and complete collapsed of the bacteria cells after 36 h of treatment. Conclusions: The significant antibacterial activity shown by crude extract suggested its potential against MRSA infection. The extract may have potential to develop as antibacterial agent in pharmaceutical use.
2.Mannanase production by Aspergillus niger USM F4 via solid substrate fermentation in a shallow tray using palm kernel cake as a substrate
Syarifah Ab Rashid ; Darah Ibrahim ; Ibrahim Che Omar
Malaysian Journal of Microbiology 2012;8(4):273-279
Aims: A local fungal isolate, Aspergillus niger USM F4 produced high level of mannanase activity when cultivated in a shallow tray system (45 x 40 x 7 cm3) using palm kernel cake (PKC), an easily available cheap agricultural waste which are found abundantly in Malaysia.
Methodology and Results: A range of 0.25 to 1.5 cm bed heights were investigated in tracking in the most suitable condition and maximum production of mannanase. The highest mannanase production of 918.68 U/g substrate was obtained on the fifth day of cultivation after using all the optimised cultural conditions that consisted of 400 g of PKC that equivalent to 0.50 cm of substrate thickness with the particle size of ≤ 0.5 mm, moisture content of 80% (w/w) with the addition of 2% (w/w) molasses as a carbon source and 4% (w/w) ammonium nitrate as a nitrogen source, inoculums size of 1x107 spores/ml, with once at every 24 h of mixing frequency and cultivation temperature at room temperature 30±2 °C.
Conclusion, significance and impact of study: The results obtained from this study showed that a shallow tray system was suitable to be used for getting highest enzyme production in SSF. Besides using a bigger volume of substrate, the correct substrate bed height is also important.
3.Characterization of cellulase, hemicellulase and lipase and its use in deinking of laser printed paper
Lee Chee Keong ; Darah Ibrahim ; Ibrahim Che Omar
Malaysian Journal of Microbiology 2013;9(1):84-92
Aims: It is recognized that laser printed paper are difficult to deink using conventional method. This had lead to the suggestion of enzymatic approach to overcome the problem encountered by commonly employed deinking techniques.
The present study aimed to investigate 7 commercially available enzymes for their suitability use in deinking of laser printed paper.
Methodology and results: 3 cellulases, hemicellulases, xylanase and 2 lipases were used in enzymatic deinking of
laser-printed wastepaper. Cellulase A “Amano”3 (C), Hemicellulase (H) and lipase (L) were selected for used in deinking because they possess either highest activity or broad pH stability compared to others enzymes. Different combination of enzymes was carried out to evaluate their effectiveness in deinking process. CH enzymes sequence was determined to be the most effective sequence in toner removal with 1.90% of brightness increment. However, only 0.95% of brightness increment was gained by enzyme sequence L. Highest deinking efficiency obtained was not proportional to the highest total reducing sugar produced.
Conclusion, significance and impact of study: Enzyme (cellulase and hemicellulase) can be used to de-ink laserprinted wastepaper, which are difficult to be deinked by conventional chemical deinking process. Thus, enzyme deinking has high possibility as alternative method to current chemical deinking process which is not environmental friendly.
4.Cytotoxicity and genotoxicity assessment of Euphorbia hirta in MCF-7 cell line model using comet assay
Ping Yuet Kwan ; Darah Ibrahim ; Chen Yeng ; Sasidharan Sreenivasan
Asian Pacific Journal of Tropical Biomedicine 2013;(9):692-696
Objective:To evaluate the cytotoxicity and genotoxicity activity of Euphorbia hirta (E. hirta) in MCF-7 cell line model using comet assay.
Methods: The cytotoxicity of E. hirta extract was investigated by employing brine shrimp lethality assay and the genotoxicity of E. hirta was assessed by using Comet assay.
Results: Both toxicity tests exhibited significant toxicity result. In the comet assay, the E. hirta extract exhibited genotoxicity effects against MCF-7 DNA in a time-dependent manner by increasing mean percentage of DNA damage. The extract of E. hirta showed significant toxicity against brine shrimp with an LC50 value of 620.382 μg/mL (24 h). Comparison with positive control potassium dichromate signifies that cytotoxicity exhibited by the methanol extract might have moderate activity.
Conclusion:The present work confirmed the cytotoxicity and genotoxicity of E. hirta. However, the observed toxicity of E. hirta extracts needs to be confirmed in additional studies.
5.Production, characterization and antibacterial activity of prodigiosin pigment produced by Pseudoalteromonas rubra BF1A IBRL associated with a marine macroalgae Enteromorpha sp.
Azlinah Mohd Sulaiman ; Darah Ibrahim ; Wan Norhana Noordin
Malaysian Journal of Microbiology 2019;15(3):226-236
Aims:
Marine bacteria are a great source of natural pigments, which can be used as colouring agent in food, textile, cosmetics and aquaculture industry to overcome the drawbacks poses by the synthetic pigments. The aim of the study is to identify the potential bio pigment producer, determine the antimicrobial susceptibilities, and characterize the pigment produced.
Methodology and results:
In this study, the surface attached marine bacteria isolated from the surface of seaweed, Enteromorpha sp. has been identified as Pseudoalteromonas rubra BF1A IBRL through the molecular identification step. This species produced intracellular and extracellular red pigment with antibacterial activity. The susceptible bacteria include Bacillus subtilis, Bacillus cereus, Methicillin Resistant Staphylococcus aureus, Staphylococcus aureus and also Acinetobacter anitratus with inhibition zone ranges from 7.33 to 10.33 mm, whereas Minimum inhibitory concentration (MIC) values ranges from 0.055 to 8.88 mg/mL. The UV/vis analysis indicated that the maximal absorbance of ISO and DE pigment extract were at 531 and 534 nm, respectively. Based on the antimicrobial activity, the extracellular extract poses greater antibacterial activity, thus was selected as the potential pigment extract and were further evaluated. The Thin Layer Chromatography (TLC) profile of the DE extract showed one major band under visible light ((Rf = 0.87) and the bioautography analysis of the pigmented band showed positive activity against both Gram-positive and Gram-negative bacteria. The pigment in DE extract was identified as prodigiosin based on the spectroscopic properties, presumptive test and HPLC analysis.
Conclusion, significance and impact of study
This study highlights the dual benefits of the P. rubra BF1A IBRL pigment extract, which exhibited both tinctorial and pharmacology benefits, thus it can be act as colouring agent with own preservative value in food, textile, or cosmetics industries.
6.Pharmacological screening of methanolic extract of Ixora species.
Lachimanan Yoga LATHA ; Ibrahim DARAH ; Kassim JAIN ; Sreenivasan SASIDHARAN
Asian Pacific Journal of Tropical Biomedicine 2012;2(2):149-151
OBJECTIVETo investigate the antimicrobial activity of methanolic extracts of different parts of Ixora species.
METHODSAntimicrobial activity was carried out using disc diffusion assay against fungi, gram-positive and gram-negative bacteria.
RESULTSAll methanolic extracts of different parts of Ixora species showed a broad-spectrum of antibacterial and antiyeast activities, which inhibited the growth of at least one bacterium or yeast. There was no remarkable difference between different Ixora species observed in this study.
CONCLUSIONSThe significant antimicrobial activity shown by this Ixora species suggests its potential against infections caused by pathogens. The extract may be developed as an antimicrobial agent.
Anti-Bacterial Agents ; pharmacology ; Antifungal Agents ; pharmacology ; Fungi ; drug effects ; Gram-Negative Bacteria ; drug effects ; Gram-Positive Bacteria ; drug effects ; Microbial Sensitivity Tests ; Phytotherapy ; Plant Extracts ; pharmacology ; Rubiaceae ; classification ; metabolism
7.Assessment of cultivation parameters influencing the growth, pigment production and anti-MRSA activity of Pseudoalteromonas rubra BF1A IBRL isolated from Malaysian marine environment
Azlinah Mohd Sulaiman ; Darah Ibrahim ; Wan Norhana Noordin
Malaysian Journal of Microbiology 2019;15(3):195-203
Aims:
Pigments are coloured substances that exhibit important characteristics to many industries including food, textile, cosmetics, food, pharmaceutical and also aquaculture industry. Naturally derived pigments from marine bacteria do not only exhibit the tinctorial property but are also known to possess broad range of antimicrobial activities. From the industrial point of view, the necessity to obtain suitable culture conditions for maximum yield of cell growth and pigment production is of utmost importance.
Methodology and results:
The effect of cultural conditions, including light, pH, temperature, agitation speed and size of inoculum on bioactivity of an epiphytic marine bacteria, Pseudoalteromonas rubra BF1A IBRL was studied using shake flask technology. The antimicrobial activity was determined using the Lorian method. As a result, prodigiosin pigment extract obtained from P. rubra BF1A IBRL showed inhibitory activity against the MRSA strain. Pseudoalteromonas rubra BF1A IBRL produced the highest level of prodigiosin and anti-MRSA activity (P<0.05) in Marine broth at initial pH of 7.6 incubated at dark condition at temperature of 26 °C, agitation speed of 120 rpm and 2% (v/v) (1 × 106 CFU/mL) of inoculums size.
Conclusion, significance and impact of study
A high correlation between pigmentation and antibacterial activity were observed anticipating that the pigment has its own antibacterial properties. The above findings supported the fact that epiphytic marine bacteria were fruitful source for pigmented bioactive compounds, and the physical parameters had significantly influence of the pigment production.
8.Assessment of cultivation parameters influencing the growth, pigment production and anti-MRSA activity of Pseudoalteromonas rubra BF1A IBRL isolated from Malaysian marine environment
Azlinah Mohd Sulaiman ; Darah Ibrahim ; Wan Norhana Noordin
Malaysian Journal of Microbiology 2019;15(3):195-203
Aims:
Pigments are coloured substances that exhibit important characteristics to many industries including food, textile, cosmetics, food, pharmaceutical and also aquaculture industry. Naturally derived pigments from marine bacteria do not only exhibit the tinctorial property but are also known to possess broad range of antimicrobial activities. From the industrial point of view, the necessity to obtain suitable culture conditions for maximum yield of cell growth and pigment production is of utmost importance.
Methodology and results:
The effect of cultural conditions, including light, pH, temperature, agitation speed and size of inoculum on bioactivity of an epiphytic marine bacteria, Pseudoalteromonas rubra BF1A IBRL was studied using shake flask technology. The antimicrobial activity was determined using the Lorian method. As a result, prodigiosin pigment extract obtained from P. rubra BF1A IBRL showed inhibitory activity against the MRSA strain. Pseudoalteromonas rubra BF1A IBRL produced the highest level of prodigiosin and anti-MRSA activity (P<0.05) in Marine broth at initial pH of 7.6 incubated at dark condition at temperature of 26 °C, agitation speed of 120 rpm and 2% (v/v) (1 × 106 CFU/mL) of inoculums size.
Conclusion, significance and impact of study
A high correlation between pigmentation and antibacterial activity were observed anticipating that the pigment has its own antibacterial properties. The above findings supported the fact that epiphytic marine bacteria were fruitful source for pigmented bioactive compounds, and the physical parameters had significantly influence of the pigment production.
9. In vitro antimicrobial activities of methanolic extract from marine alga Enteromorpha intestinalis
Asian Pacific Journal of Tropical Biomedicine 2015;5(9):785-788
OBJECTIVE: To extract the bioactive compound from Enteromorpha intestinalis (E. intestinalis) and determine its in vitro antimicrobial activity. METHODS: E. intestinalis was extracted by methanol and subjected to antimicrobial screening. The antimicrobial activity was studied by using disc diffusion and broth dilution method. The effect of the extract on the growth profile of the bacterial was also examined via time-kill assay. Microscopy observations using SEM was done to determine the major alterations in the microstructure of methicillin-resistant Staphylococcus aureus (MRSA). RESULTS: The results showed methanolic extract of E. intestinalis exhibited a favourable antimicrobial activity against tested bacteria with produced inhibition zone ranging from 8.0 to 19.0 mm. However, all the tested fungi and yeast were resistant to the extract treatment. Time kill assay suggested that methanolic extract of E. intestinalis had completely inhibited MRSA growth and also exhibited prolonged antibacterial activity. The main abnormalities noted from the microscopic observations were the structural deterioration in the normal morphology and complete collapsed of the bacteria cells after 36 h of treatment. CONCLUSIONS: The significant antibacterial activity shown by crude extract suggested its potential against MRSA infection. The extract may have potential to develop as antibacterial agent in pharmaceutical use.
10.Antimicrobial activity of Aspergillus sp. IBRL MP15 CCL, an endophytic fungus isolated from Swietenia macrophylla leaf against human pathogens
Chean Ring LEONG ; Adib Arifah Binti Mansur ; Syarifah Abdul RASHID ; Swee Ngim ANG ; Wen-Nee TAN ; Woei Yenn TONG ; Darah IBRAHIM
Malaysian Journal of Microbiology 2018;14(1):49-54
Aims: Endophytes are microorganisms residing in the living tissues of the host plant and may contribute to their hostplant by producing a plethora of bioactive compounds that provide survival value to the plant. This study aimed toevaluate the antimicrobial activity of Aspergillus sp. IBRL MP15 CCL, an endophytic fungus isolated from Swieteniamacrophylla leaf.Methodology and results: The antimicrobial activity was evaluated with disc diffusion and a colorimetric brothmicrodilution test against 15 organisms comprising of 4 Gram-positive bacteria and 4 Gram-negative bacteria, 4 fungiand 3 yeast. On disc diffusion assay, the fungal extract was shown to inhibit the growth of 7 test bacteria and 3 testyeast. The antibacterial activity was more pronounced with extract from fungal culture with host plant extractsupplementation with significantly larger inhibition zones on all susceptible test microorganisms. The minimal inhibitoryconcentration of the extract ranged from 250 to 4000 μg/mL indicating different level of susceptibility of the testedpathogens against the fungal extract. The killing kinetic study shows that antimicrobial activity of the fungal extract isconcentration dependent and it can act as bactericidal at higher concentration.Conclusion, significance and impact of study: The findings of this study suggest that Aspergillus sp. IBRL MP15CCL can be a promising source of antimicrobial agent to be further studied and developed