## 3 Results and Discussion
### Phylogenetic Analysis of the 2 GPP Selected Strain
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**24 h**} & \multicolumn{3}{c}{**48 h**} \\ \hline
**Inoculum** & **Lactic Acid** & **1,3-Propanediol** & **Lactic Acid** & **1,3-Propanediol** & **Y\({}_{\text{LA/Gly}}\)** & **Y\({}_{\text{1,3-PDO/Gly}}\)** \\
**Concentration (g\(\cdot\)L\({}^{-1}\))** & **(g\(\cdot\)L\({}^{-1}\))** & **(g\(\cdot\)L\({}^{-1}\))** & **(g\(\cdot\)L\({}^{-1}\))** & **(g\(\cdot\)L\({}^{-1}\))** & **Y\({}_{\text{LA/Gly}}\)** & **Y\({}_{\text{1,3-PDO/Gly}}\)** \\ \hline
5.0 (120 rpm) & 1.00 \(\pm\) 0.09 & 0.61 \(\pm\) 0.09 & 1.94 \(\pm\) 0.41 & 1.28 \(\pm\) 0.20 & 0.54 & 0.36 \\
4.2 (120 rpm) & 1.10 \(\pm\) 0.13 & 0.87 \(\pm\) 0.14 & 1.43 \(\pm\) 0.21 & 1.09 \(\pm\) 0.21 & 0.41 & 0.31 \\
2.0 (120 rpm) & 0.79 \(\pm\) 0.12 & 0.53 \(\pm\) 0.11 & 1.34 \(\pm\) 0.13 & 0.97 \(\pm\) 0.27 & 0.38 & 0.28 \\
1.0 (120 rpm) & 0.81 \(\pm\) 0.19 & 0.68 \(\pm\) 0.25 & 1.29 \(\pm\) 0.13 & 0.94 \(\pm\) 0.59 & 0.37 & 0.26 \\
4.2 (unstirred) & 2.29 \(\pm\) 0.02 & 1.48 \(\pm\) 0.01 & 2.88 \(\pm\) 0.39 & 1.91 \(\pm\) 0.27 & 0.81 & 0.55 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Evaluation of the production of lactic acid by _Klebsiella_ sp. 2 GPP with glycerol as carbon source and variations in inoculum in a 15 mL flask. As 1,3-propanediol and lactic acid compete for the same substrate (glycerol), to improve lactic acid bioconversion, experimental conditions were analyzed to minimize the production of 1,3-propanediol. This was a challenge, since a preferential and simpler route produces 1,3-propanediol. In addition, the separation of compounds is not trivial and generates more costs [9]. \({}^{1}\)H NMR was used to reaffirm the production of lactic acid and 1,3-propanediol as the main metabolites at the end of fermentation. After microaneorbiosis fermentation with 2 GPP, the spectrum represented in Figure 3 was obtained. The signals of L-(+)-lactic acid and 1,3-propanediol were assigned. Signals \"a\", \"b\" and \"c\" are related to the lactic acid molecule. The hydrogen of the chiral carbon is characterized by the chemical shift of 4.11 ppm, indicated by \"a\". Methyl group was indicated by the \"b\" signal in doublet form at 1.14 ppm. The hydroxyl hydrogen was assigned to the doublet indicated by \"c\" at 3.55 ppm. Signals \"d\", \"e\" and \"f\" were assigned to the 1,3-propanediol molecule. The hydrogen indicated by the letter \"d\" is a quintuplet with a chemical shift of 1.33 ppm. The triplet \"e\" at 3.78 ppm indicates two-carbon hydrogens with the same chemical environment. The hydroxyl hydrogens were assigned to the triplet indicated by \"f\" at 3.65 ppm. In the present work, HPLC measurements were carried out to provide insight into the production of lactic acid enantiomers. According to Figure 4, the 2 GPP strain was able to produce L-(+)-lactic acid with optical purity (retention time of 2.77 min). From the chromatogram obtained for the pure enantiomer samples, the retention time for L-(+)-lactic acid and D-(--)-lactic acid was expected to be equal to approximately 2.70 min and 9.75 min, respectively (Figure 4A). As depicted in Figure 4B, only the L-isomer was produced, since no signal was detected at about 9.8 min. The signals detected at retention times within the interval from approximately 1.0 min to 2.6 min were related to other species in the fermentation medium. This finding differs from the work developed by [PERSON] et al. [49]. According to this study, wild-type _Klebsiella oxytoca_ produced approximately 2.7 g\(\cdot\)L\({}^{-1}\) of D-(-)-lactate during glucose fermentation, reaching a yield of 0.12 g\(\cdot\)g\({}^{-1}\) and productivity of 0.11 g\(\cdot\)L\({}^{-1}\cdot\)h\({}^{-1}\) after 72 h, along with ethyl alcohol, 2,3-butanediol, succinate, acetate and formate. Figure 3: \({}^{1}\)H NMR spectrum related to the end of fermentation containing lactic acid and 1,3-propanediol.