Genes related to arginine metabolism. A) Two clusters of L. lactis IL1403 genes related to arginine metabolism. B) A L. lactis MG1363 gene cluster correlated to arginine metabolism. Colours represent strength of relationship between a gene and a phenotype (Figure 1). Phenotypes are either shown as last digits in column names or with suffixes “high” or “low”, where 0 indicates no growth and other numbers indicate different growth levels as described in the Additional file 1. Here “high” and “low” phenotypes indicate high and low enzyme activity levels, respectively. For gene annotations see Additional file 3.