Toxicology International (Formerly Indian Journal of Toxicology)

Shilpi Srivastava ¹, Neelam Pathak ², Prachi Srivastava ¹

Affiliations
1 Amity Institute of Biotechnology, Amity University Uttar Pradesh (Lucknow Campus), Lucknow - 226 010, IN
2 Department of Biotechnology, Integral University, Lucknow - 201 126, Uttar Pradesh, IN

Abstract

Fusarium oxysporum is a highly ubiquitous species that infects a wide range of hosts causing various diseases such as vascular wilts, yellows, rots, and damping-off. Despite the immense economic significance of this phytopathogen, few workers have reported growth studies in this genus in submerged culture. In the present study, several parameters such as change in media pH, biomass, pattern of substrate utilization, viability of the fungal cells, and protein content were observed over a period of time. The fungal biomass increased at a slow rate for the initial 48 h and thereafter increased at an exponential rate. However, after about 8 days the rapid growth stabilized and the trend became more toward stationary phase. The concentration of glucose in the liquid media decreased rapidly up to the initial 4 days, followed by a slow decrease. The pH of the medium gradually decreased as the fungal growth progressed, the reduction being more pronounced in the initial 48 h. This study would be of immense importance for utilization of F. oxysporum for diverse applications because we can predict the growth pattern in the fungus and modulate its growth for human benefit.

Keywords

Biomass production, Fusarium, glucose utilization, MTT assay, protein

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Manikant Tripathi ¹, Neelam Pathak ², Vinod Kumar Chaudhary ³, Pankaj Singh ¹, Pradeep Kumar Singh ², Banjagere Veerabhadrappa Thirumalesh ⁴, Saroj Bala ⁵, Avnish Kumar Maurya ², Naveen Patel ⁶, Brijesh Kumar Yadav ³

Affiliations
1 Biotechnology Program, Dr. Rammanohar Lohia Avadh University, Ayodhya - 224001, Uttar Pradesh, IN
2 Department of Biochemistry, Dr. Rammanohar Lohia Avadh University, Ayodhya - 224001, Uttar Pradesh, IN
3 Department of Environmental Sciences, Dr. Rammanohar Lohia Avadh University, Ayodhya - 224001, Uttar Pradesh, IN
4 Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram - 695019, Kerala, IN
5 Department of Microbiology, Punjab Agriculture University, Ludhiana - 141001, Punjab, IN
6 Department of Civil Engineering, IET, Dr. Rammanohar Lohia Avadh University, Ayodhya - 224001, Uttar Pradesh, IN

Abstract

In the recent past, one of the main environmental issues is the contamination of textile dye wastes. The toxicity of dyes poses adverse effects on the flora and fauna of the ecosystem. The present study aimed to isolate bacteria that decolourize crystal violet dye, optimization of various environmental factors for effective decolourization, and phytotoxicity analysis. Out of 13 isolated bacteria, a single isolate was able to grow at 250 mg/L crystal violet dye concentration in a synthetic medium and identified as Aeromonas caviae MT-1 strain (accession number; LC720408) using morphological, biochemical and molecular analyses. Presumably, this is the first report of crystal violet dye decolourization by a native Aeromonas caviae isolate. In this study, after a 72-hour incubation period, a maximum of 98.0% dye decolourization was observed at neutral pH and 35°C with 5% v/v bacterial culture under static culture conditions. Dye decolourization was inhibited to a significant degree by the rising of its concentration. UV-Vis spectra analysis of samples before and after decolourization showed the possible degradation of crystal violet dye by A. caviae. The strain MT-1 was also tolerant to toxic heavy metals like arsenic, lead, and chromium. Phytotoxicity tests revealed that decolourized dye products inhibited Vigna radiata growth less than the un-decolourized dye solution. The findings revealed that a native multi-metal tolerant A. caviae MT-1 isolate could decolourize crystal violet dye rapidly, and possibly have the ability for extensive treatment of dyecontaminated waste.

Keywords

Aeromonas caviae, Crystal Violet Dye, Decolorization, Heavy Metals, Phytotoxicity, Waste Treatment

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