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Summary: The present study provided a new alternative for efficiently producing lipopeptides by calcium lactate and expanded potential applications of lipopeptides for ensuring food safety. The results indicated that the addition of calcium lactate significantly improved bacillomycin D production. When fed 150 mL of fermentation medium with 6.5 g/L calcium lactate at the batch fermentation time of 102 h, the maximum production of C14 bacillomycin D (C14BD), C15 bacillomycin D (C15BD), C16 bacillomycin D (C16BD), C17 bacillomycin D (C17BD) and total C14‐17 bacillomycin D (TBD) were 298.96, 345.43, 149.56, 216.6 and 1010.55 mg/L at 162 h, respectively. In addition, calcium lactate effectively induced biosynthesis of bacillomycin D through upregulating 2‐ketobutyric acid in the valine, leucine and isoleucine biosynthesis (VLIB) pathway that was closely related to threonine dehydratase and threonine and increasing expression of bacillomycin D synthase genes. Moreover, bacillomycin D could remarkably inhibit spore germination of Aspergillus flavus in rice. [ABSTRACT FROM AUTHOR]

Summary: l‐lactate is a conjugate base of α‐hydroxy acid, a key organic chemical in food processing, fermentation, biology and chemical industries. We are reporting for the first time a facile and rapid non‐enzymatic nanosensor for l‐lactate detection in tomato‐based products using 3‐aminophenylboronic acid (3‐APBA)‐added zinc oxide nanoparticles (ZnO NPs). 3‐APBA‐functionalised ZnO NPs have a selective and stable SPR intensity change at pH 5.5 to 7.5 and forms a reversible ester with bound l‐lactate revealing the wavelength shift from λ = 300 nm to 288 nm in UV‐VIS absorption spectrometry. In the spiked (2.5–20 mm) samples of tomato puree, absorption peak increased as per l‐lactate addition with the lower detection limit of 3.98 mm. l‐lactate binds with a trigonal form of 3‐boronate, thereby generating the tetrahedral complex. ZnO NPs stabilise the tetragonal complex. Nanosensor validated with standard HPLC. This method is useful for l‐lactate detection and alternates to conventional techniques. [ABSTRACT FROM AUTHOR]