Characteristics Bacterial strain GSM2 Catalase - Oxidase + Urease + Citrate utilization - Nitrate reduction + Glucose + Adonitol + Lactose - Sorbitol + Esculin hydrolysis - Xylose - Maltose + Fructose + Galactose - Raffinose - Trehalose + Melibiose - Sucrose + L-Arabinose + Mannose + Inulin + Sodium gluconate + Glycerol + Salicin + Dulcitol + Inositol + Mannitol [+] Arabitol + Erythritol [+] [alpha]-Methyl-D-glucoside + Rhamnose + Cellobiose + Melezitose + [alpha]-Methyl-D-mannoside - Xylitol - ONPG - D-Arabinose + Malonate utilization + Sorbose
- +: positive, [+]: weakly positive, and -: negative.
Further identification to species level were based on carbohydrate fermentation using 1% solution of following sugars: glucose, lactose, mannitol, sucrose, arabinose, sorbose
, sorbitol, raffinose, ribose, trehalose, xylose, melibiose, glycerol; by pigment production, motility test, pyruvate utilization in 1% pyruvate broth, acidification of methyl-alpha-D-glucopyranoside, Voges-Proskeuer test, arginine decarboxylation, hippurate hydrolysis, reduction of potassium tellurite and tetrazolium chloride.(4,5,6)
Out of nine C sources (glucose, galactose, dextrin, lactose, maltose, sorbose, xylose, fructose, sucrose) and six N sources (urea, ammonium chloride, ammonium sulphate, ammonium nitrate, ammonium phosphate, potassium nitrate and sodium nitrate) tested, 12% dextrin and 2% ammonium sulphate revealed the best results, yielding up to 60.8 g glutamic acid /L (50% enhancement) after 48 h fermentation.
For optimising the C source, we used L-6 medium (pH 7) containing Trypticase (0.75%), CaCO3 (2%), KH2PO4 (0.07%), K2HPO4 (0.4%), MgSO4.7H2O (0.03%), (NH4)2SO4 (0.03%), Biotin (60 ug/l), Thiamine HCl (5 mg/l) and the C source (10 %) either glucose, galactose, lactose, maltose, sorbose, xylose, fructose, sucrose or dextrin.
Both cr-5 and wild type 74A were grown on minimal medium in which the carbon source was 2% sucrose, 2% glucose, 2% fructose, 2% lactose, 2% mannitol, 2% glycerol, or 2% sorbose
. The cr-5 mutant grew better on glucose and fructose separately than it did no sucrose alone.
This bacteria was found to be able to hydrolyze various carbohydrates, including L-arabinose, galactose, fructose, mannose, [alpha]-methyl-D-glucoside, N-acethyl-glucosamine, D-turanose, salicin, cellobiose, [beta]-gentiobiose, and D-xylose (Table 1), but did not utilize D-arabinose, erythritol, sorbose
, dulcitol, inositol, [alpha]-methyl-D-mannoside, Lactose, D, L-arabitol, 2-keto-gluconate, or 5-keto-gluconate (Table 1).
The L5 strain could utilize fructose, D-glucose, and mannose; but did not utilize sorbose
, inulin, or inositol.