Most of the plant

derived strains fermented D-mannitol, amygdaline, potassium gluconate, l-arabinose, d-xylose, sucrose and gentibiose, but none of the dairy control strains were able to utilize any of these carbohydrates (data not shown) A recent genomic analysis on plant derived Lactococcus confirmed the presence of gene clusters that code for the degradation check details of complex plant polymers such as arabinan, xylan, glucans and fructans and for the uptake and conversion of the plant cell wall degradation products, such as α-galactosides β-glucosides, arabinose, xylose, galacturonate, glucuronate and gluconate as plant derived energy sources ( Siezen et al., 2010 and Siezen et al., 2011). All subsp. lactis isolates were able to coagulate milk (10% RSM) although at different rates (18 to 48 h). The two subsp. cremoris strains (M23-10 and M16-10) failed to coagulate milk even after extended incubation of 7 days. However, these cremoris Selleck Cyclopamine strains fermented milk in less than 18 h when the culture was supplemented with 0.5% glucose

( Table 2). The results show that the two cremoris strains have a functioning proteolytic system but compromised lactose utilization ability. A similar result has been reported recently by Gutiérrez-Méndez et al. (2010) where plant L. lactis isolates showed the slowest growth rates and yield when lactose was used as energy source, compared to those obtained when glucose was used as carbohydrate source. In Terminal deoxynucleotidyl transferase ten of the plant lactococci isolates no plasmid was detected. One plasmid each was detected in two of the subsp. lactis isolates (P-21 and C-3) with size ranging between 80 and 90 kb (data not shown). Previous studies have clearly established

that the majority of strains of dairy L. lactis depend on plasmids for lactose utilization, casein degradation, citrate utilization, bacteriocin production, bacteriophage resistance and slime formation ( LeBlanc et al., 1980, McKay, 1983, Teuber, 1995 and Mills et al., 2006). Based on the PFGE DNA finger-printing data, the isolates could be identified as 10 distinct strains (Fig. 1). Two grass isolates 144-L and 144-S showed identical restriction pattern and thus assumed to be the same strain. The other two fresh green pea isolates, P-5 and P-8 also showed identical restriction patterns and growth characteristics and were assumed to be the same strain (Fig. 1). The formation of volatile flavour compounds in dairy products is a complex process resulting from glycolysis, lipolysis and proteolysis of milk components which is mediated by the enzymatic mechanisms of the microflora contained within the product (McSweeney and Sousa, 2000, Smit et al., 2004). However, the production of flavour compounds in fermented dairy products is strain dependent and therefore the composition of the starter mix can greatly influence the flavour profile (Kieronczyk et al., 2003).