Development of a bacterial gene transcription activating strategy based on transcriptional activator positive feedback

•Transcription activation by positive regulators and their regulating sequences.•Positive regulator stimulates transcription of itself and downstream genes.•Higher transcription activation than strong constitutive promoters.•Demonstrated in Pseudomonas stutzeri, Escherichia coli and Streptomyces albus.•Highest yields of indole-3-acetic acid and prodigiosin in heterologous hosts.