IOSR Journal of Agriculture and Veterinary Science (IOSR-JAVS) e-ISSN: 2319-2380, p-ISSN: 2319-2372. Volume 9, Issue 4 Ver. I (Apr. 2016), PP 84-86 www.iosrjournals.org DOI: 10.9790/2380-0904018486 www.iosrjournals.org 84 | Page Exploring the role of Bacillus species in combating Aluminium toxicity in Zea mays by studying its effect on chlorophyll content Priyanka Arora 1 , Geeta Singh 2 and Archana Tiwari 1* 1 School of Sciences, Noida International University, G.B Nagar, Greater Noida, U.P 2 Division of Microbiology, Indian Agricultural Research Institute (IARI), New Delhi *corresponding author: panarchana@gmail.com Abstract: Aluminium is one of the major components that are present in soil and it forms complexes with oxygen and silicates. These complexes are stable and rapidly soluble in soil water under low pH conditions. Some microorganisms present in soil have great potential to survive under these acidic conditions. The present study was aimed to check the effect of aluminium toxicity on Bacillus species when their growth media was supplemented with 20mM AlCl 3 concentration. Experimental results depicted that Bacillus had best survival at 20mM AlCl 3 concentration. Surprisingly it showed an increase of ̴ 80% in bacterial growth under 20mM aluminium toxic conditions as compared to unstressed condition, implying that Bacillus species which were isolated from soil have growth optima at low pH values. When this combination was applied to germinate maize seeds in acidic conditions , the maize seeds showed ̴ 15% increase in chlorophyll content of their leaves in comparison to the control leaves without any bacterial inoculation under stressed conditions. In the light of the findings, it can be concluded that the problem of aluminium toxicity can be addressed efficiently by using microbes and there can be significant enhancement of growth parameters as well. Key words: Bacillus, Zea mays, Aluminum, chlorophyll, Toxicity I. Introduction Heavy metals are generally naturally occurring in the earth‟s crust but now-a-days various anthropogenic sources viz., industrial effluents, mining, dumping of sludge are found to be responsible for introducing these heavy metals to environment on regular basis [1]. Heavy metal in present era forms an important class of pollutants. Their retention in the environment exerts hazardous effects both on flora as well as fauna [2]. It has been found that higher concentration of these heavy metals have become one of the major limiting factor for production of crops leading to a loss in sustainable agriculture [3,4]. These heavy metals may interact with active sites of enzymes and nucleic acids thereby leading to cell death [5,6,7]. Acidic soils contribute to almost 40% of the world‟s arable soils presenting various toxi city hazards to various species [8]. Increase in the concentration of heavy metals may adversely affect metabolic activities of various microbes. Aluminium is one of the most abundant heavy metals that is found in earth‟s crust contributing approximately 7% [9]. It has been found to have various negative effects on growth and development of major crops in acid soils [10,11,12]. Plants take up free aluminium ions from acidic soils [13]. Also, under circumstances where aluminium concentrations are higher in soil, the above ground parts of plants are found to have impaired development [14]. The epidermal cells lose their turgidity due to changes in their cell membrane permeability thereby damaging the epidermal layer of major plant parts [15]. Necrosis of leaves has been found under aluminium toxic conditions. The phosphorus and calcium levels also lowers down in presence of aluminium thus leading to death of shoot tips. The aim of present research was to study the tolerance level of bacterial cultures under aluminium toxic conditions and to study the combined effect of bacterial spp. and aluminium toxicity on total chlorophyll content of leaves grown under control as well as stressed condition. II. Materials and Methods Microorganisms, Growth medium and Culture conditions Bacillus spp. resistant to high aluminium concentration was isolated from north east soil (soils with acidic pH). Isolation was carried out on nutrient broth fortified with different concentrations of aluminium (0, 20, 60, 80mM AlCl 3 ). The fortified medium was dispensed in tubes in triplicates. The Bacillus spp. was then inoculated aseptically in the medium in laminar air flow. The inoculated media was put on shaker for 24-48 hrs at 37°C and then O.D. was taken at 600nm to check aluminium tolerance of inoculated Bacillus spp. Determination of total chlorophyll content Maize seeds inoculated with selected Bacillus spp. were grown in soil bearing aluminium stress. The leaves from such plants were taken to estimate variation in total chlorophyll content under aluminium stressed