LSQ vs. NSQ: ↓, decreased in LSQ; ↑, increased in LSQ. NLB vs. LB: ↓, decreased in NLB; ↑ increased in NLB. Number indicates the Fold change for each of the pairwise comparison. Metabolites with *p<0.1, or |Fold change|>2.0 are labeled with increase or decrease for the comparison. --, indicates no change. OL2b, PDA, PDb: metabolites in the enriched pathway were verified by matching against the in-house physical standard library with MS, MS/MS (OL2b), or matching against the public database with MS, experimental MS/MS (PDA), MS, theoretical MS/MS (PDb)