Kunasundari Balakrishnan
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Kunasundari Balakrishnan
Official Name
Balakrishnan, Kunasundari
Alternative Name
Balakrishnan, K.
Kunasundari, B.
Kunasundari, Balakrishnan
Main Affiliation
Scopus Author ID
37861493500
Researcher ID
DBC-0761-2022

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Isolation of alkali-thermotolerant cellulolytic bacteria from spent mushroom substrate

2020 , N Y Hasnol Azahari , S Naresh , S N A Rozani , Kunasundari Balakrishnan

In this study, the isolation of new alkali-thermophilic bacteria with enhanced cellulase producing ability from the spent mushroom substrate was conducted. Repeated streaking was performed on the Microcrystalline-cellulose (MCC) to obtain a pure culture. Two thermophiles bacteria isolates were used for subsequent experiment. Morphological characteristic by gram staining and endospore staining also genetic identification of 16S rDNA was performed and the growth profile had been generated using Polymath Software. Filter paper assay (determination of enzyme activity), Bradford protein concentration were used in plotting the growth associated product curve. Based on the 16S rDNA sequencing results, the bacterium strains of Anoxybacillus geothermalis, incubated at 50ËšC, pH 7 and Aeribacillus pallidus, incubated at 60ËšC, pH 8 was successfully isolated. Both strains are gram-positive and endospore-forming bacteria. Based on the growth curve, the doubling time for Anoxybacillus geothermalis was calculated to be 49.5 minutes. Whereas, doubling time of Aeribacillus pallidus was 56.7 minutes. Both strains represent the growth assosiated product curve in which, when product formation is growth associated the specific rate of the product formation increases with specific growth rate and vice versa.

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Isolation and characterization of laccase secreting microorganism from Gua Kelam 2, Perlis

2023 , Natasha Yasmin Hasnol Azahari , Nor Anis Syafiqah Suhaily , Sandrasekaran Naresh , Mohamad Fahrurrazi Tompang , Kunasundari Balakrishnan

The current study, involves isolation and characterization of laccase producing microbes from Gua Kelam 2, Perlis, Malaysia. In our study, all isolates were cultivated on nutrient agar containing guaiacol. Only one isolate (GK1) was detected as a positive laccase producer which was then subjected for growth curve and kinetic analysis using nutrient broth and minimal salt medium. For nutrient broth, short exponential phase was recorded from 2nd h until 4th h in contrast to minimal salt medium that exhibited exponential phase from 8th h until 24th h. The highest laccase activity was recorded in nutrient broth (4.50 U L-1) at 4th h incubation compared to minimal salt medium (3.72 U L-1) at 30 h. The isolate GK1, was characterized to be rod shape and Gram positive bacterium. Based on the 16S rRNA sequencing, the isolate determined to be Bacillus subtilis.

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Optimization of on-site Xylanase production from Aspergillus niger via Central Composite Design (CCD)

2020 , M Tarrsini , Ng Qi Hwa , Y P Teoh , Kunasundari Balakrishnan , W U Ang , S H Shuit , Z X Ooi , Hoo Peng Yong

Xylanases have stimulated considerable interest due to their potential application in several industries, especially in the bioethanol sector. Since the vitality of this enzyme is undeniable, this research is focused on optimization of on-site xylanase production from Aspergillus niger (A. niger). This initiative could reduce the dependence of commercial xylanase. Central Composite Design (CCD) was implemented in the process of xylanase production optimization. Incubation temperature and medium pH were two parameters selected to statistically optimized using Response Surface Methodology (RSM) in order to improve the xylanase production. From the data analyzed by Design of Experiment (DoE), maximal xylanase production was predicted to produce under condition of 32.67 °C and pH 4.56 with desirability of 0.936. A validation test with triplicate was done to verify the predicted result. The maximum enzyme activity of 0.5638 U/mL was obtained from the validation test.

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Isolation and characterization of polyhydroxyalkanoate producing microorganisms from molasses wastewater

2023 , Natasha Yasmin Hasnol Azahari , Naresh Sandrasekaran , Deiyban Rau , Mohamad Fahrurrazi Tompang , Kunasundari Balakrishnan

Polyhydroxyalkanoates (PHAs) are polyesters generated by numerous microorganism, where it served as a source of energy and carbon store for bacteria. These plastics are biodegradable, eco-friendly and recyclable. In the present study, 2 strains were successfully isolated and identified from molasses wastewater using staining with Nile Red A. Genotypic identification revealed that the isolates belong to species of Pseudomonas alcaliphila and Pseudomonas hydrolytica. Growth curves of both strains were constructed using POLYMATH software showed similar growth patterns and rates. The PHA accumulation of Pseudomonas alcaliphila and Pseudomonas hydrolytica were recorded at 55% and 45% of dry cell weight. The PHA functional group was further determined through Fourier Transfer InfraRed Spectroscopy (FTIR) analysis.

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Structural and composition modification of Harum Manis mango (Mangifera indica) leaves via chemical pretreatment for bioethanol production

2023 , Mahadevan Tarrsini , Ng Qi Hwa , Yi Peng Teoh , Siew Hoong Shuit , Zhong Xian Ooi , Kunasundari Balakrishnan

Harum Manis mango leaves are considered lignocellulosic (LC) biomass that could contribute to the production of second generation (2G) bioethanol. However, pretreatment should be conducted to overcome the recalcitrance of LC biomass prior to bioethanol production. Hence, this study aims to elucidate the structural changes of the biomass of Harum Manis mango leaves after single-stage and two-stage chemical pretreatment. The Harum Manis mango leaves were treated with only acid, only alkaline, acid-alkaline, or alkaline-acid process. One per cent (v/v) sulphuric acid and 1% (w/v) sodium hydroxide were used as the acid and alkaline hydrolysing agent in the four approaches of pretreatment, respectively. Consequently, the pretreated biomass was enzymatically hydrolysed to produce reducing sugar followed by the conversion into bioethanol through yeast fermentation. Acid-alkaline pretreatment yielded the highest holocellulose composition of 95.26%, with the highest delignification effect of 86.97 ± 1.26%. Furthermore, Fourier transform infrared (FTIR) spectroscopy and X-ray powder diffraction (XRD) validated the acid-alkaline pretreated biomass to be the most feasible substrate for bioethanol production in this study. Finally, the maximum fermentable sugar content and bioethanol concentration of 415.02 ± 7.01 mg/g and 1.57 ± 0.06 mg/ml, respectively, were obtained.

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Study of albumen as foaming agent for use in self-healing high strength concrete

2023 , Zuhairiah Zainal Zainal Abidin , Muhd Afiq Hizami Abdullah , Kunasundari Balakrishnan , Muhammad Munsif Ahmad , Nurul Ain Harmiza Abdullah , Mohd. Mustafa Al Bakri Abdullah , Q. A. Musa

Self-healing is an effective solution for sustainable maintenance for concrete to increase its durability against to sensitivity of cracking. As recently, the method of introducing bacterial agent in concrete were modified because of harsh environment in concrete such as small size of pore which cause squeezing of bacteria. In this research, the albumen from egg was used as foaming agent to create voids in concrete matrix. The aerated concrete matrix offer voids to bacteria as concrete will become dense and bacteria would squeezed during hydration process. The effect of albumen as foaming agent in concrete was studied while achieving the high strength aerated concrete type towards its compressive strength, splitting tensile strength and study the voids dissolution (visual) in concrete matrix when incorporation of albumen as foaming agent. The albumen of 2%, 4% and 6% is used as foaming agent (FA) to produce the high strength aerated concrete (HSAC). After 28 days of curing, the compressive and splitting tensile strength of HSAC reduced with the increased of albumen used in concrete. The highest compressive and splitting tensile strength of HSAC were 95.40 MPa and 6.67% respectively with 2% FA in comparison to control. The results of water absorption of HSAC also decreased when higher concentration of albumen used. The sizes of voids created in all samples were less than 15 mm. It can deduced that 2% of foaming agent was ideal to produce optimum characteristics in strength, uniform and size of voids in high strength aerated concrete.

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Screening of process parameters to produce Xylanase from Aspergillus niger for secondary bioethanol production

2020 , M Tarrsini , Ng Qi Hwa , Y P Teoh , Kunasundari Balakrishnan , W U Ang , S H Shuit , Z X Ooi , Hoo Peng Yong

In recent years, the biotechnological use of xylanases has grown remarkably. Xylanase is a hydrolytic enzyme with a broad industrial application. In specific, xylanase can convert xylan into xylose, a fermentable sugar source for secondary bioethanol production. The objective on this study is to investigate the significance of different parameter effects for an efficient xylanase production from Aspergillus niger (A. niger). In this study, four factors: incubation temperature, medium pH, incubation time, and agitation speed were screened by performing One-factor-at-a-time (OFAT) analysis. Xylanase production with the maximal enzyme activity was successfully obtained from OFAT analysis under condition of 32°C, pH 5.0, 5 days, and 150 rpm.

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