Table 5 Results of Pearson’s correlation coefficient (r) (n=29) between different parameters

Parameters	ORO	Ca2+ content	Colony count
Yield of polypeptides	0.719**	0.749**	0.768**
Ca2+ content	1	0.810**	0.691**
Colony count		1	0.767**

ORO, obtaining rate of oligopeptide.
r values were obtained using IBM SPSS statistics V 21.0. ANOVA were carried out using Statistix 8.1.
^** p<0.01.