TABLE 2.

The influence of various conditions on peptide production of circularin A with the constructed stain (pTLR4-CirABCDE).

Parameters	Peptide productiona
Standard conditions:
(1) Growth medium: Minimum Essential Medium (MEM) supplemented with 0.5% glucose, 1% glycerol, 5 μg/ml erythromycin; (2) Induced with 10 ng/ml nisin at the growth stage of OD600 ∼ 0.5.	++
Changed parameters:
Nisin-induction from the beginning	+++
0.5% glucose + 50 mM sucrose (∼1.7%, w/v) in growth medium	+++
0.5% (+1.7%) glucose in growth medium	+++
No erythromycin in growth medium	++
No glycerol in growth medium	+

^aCircularin A production under standard conditions is set as 100% for comparison. The relative peptide yield for each altered parameter is estimated based on the amount of peptide obtained from peptide purification, and is shown on a scale of 0–10% (±), 10–50% (+), 50–150% (++), 150–500% (+++).