NOVELTY - A microbial composition (I) comprising bacterial strains having characteristics similar to Bacillus alkalophilus and Bacillus sp. deposited in culture collection ATCC as No.27647 and 27557 respectively (or a mutant or variant), is new.    USE - (I) is useful for neutralization of alkaline waste-water, comprising reconstituting lyophilized bacterial powder obtained in (l) by adding 50 ml distilled water, adding 10% reconstituted bacterial strains to alkaline waste-water containing phenol red indicator and optionally 1% carbohydrate and observing acid production by a change in the indicator color and by measuring decrease in pH of the medium and the alkaline waste-water to neutral, after 2 days (claimed).    ADVANTAGE - Neutralization of alkaline waste-water using (I) is economical and highly safe as usage of tones of acid to neutralize the waste-water is eliminated.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for the preparation (II) of (I), comprising:    (a) isolating bacterial strain Bacillus alkalophilus and Bacillus sp. from sewage;    (b) inoculating the bacterial strains in an alkaline Bacillus broth medium containing MgSO4;    (c) growing the strains for 16-24 hours;    (d) inoculating the bacterial strains from (c) in modified Tryptone soya broth (TSB) medium of original pH 7 adjusted to different pH values ranging between 8-11 using Tris-HCl buffer and NaOH-Na2CO3 or NaHCO3-Na2CO3 buffer under sterile conditions;    (e) growing the strains obtained from (d) in modified TSB medium for 16-24 hours at different pH values ranging from 8-11, to select the bacterial strains growing at pH 11 and the remaining bacterial strains unable to grow at pH 11 being acclimatized at pH 11;    (f) inoculating the selected acclimatized bacterial strains from (e) in a modified nutrient broth medium of pH 7 adjusted to different pH values ranging between 9-11 using NaOH-Na2CO3 or NaHCO3-Na2CO3 buffer under sterile conditions;    (g) adding a dye, phenol red indicator and optionally 1% carbohydrate to the inoculated medium of (f) to observe the change in color caused by acid production and to identify the acid producing strains at pH 9-11;    (h) growing the inoculated strains for 2 days and absorbing acid production by changing color of phenol red from red to orange and from orange to yellow and by measuring the decrease in pH of the medium;    (i) selecting the acid producing bacterial strains at pH 11;    (j) mixing the selected bacterial strains to obtain a mixed bacterial suspension and centrifuging at 8000-12000 rpm to obtain a pellet;    (k) washing the pellet by suspending in triple distilled water and recentrifuging at the same rpm; and    (l) collecting the pellet from (k) and lyophilizing the obtained pellet.