Hyaluronic acid production by Klebsiella pneumoniae strain H15 (OP354286) under different fermentation conditions

Abstract

Abstract Background Hyaluronic acid (HA) has gained significant attention due to its unique physical, chemical, and biological properties, making it widely used in various industries. This study aimed to screen bacterial isolates for HA production, characterize favorable fermentation conditions, and evaluate the inhibitory effect of bacterial HA on cancer cell lines. Results A total of 108 bacterial isolates from diverse sources were screened for HA production using HPLC, turbidity, and carbazole determination methods. Among the HA-producing isolates, Klebsiella pneumoniae H15 isolated from an animal feces sample, was superior in HA production. The strain was characterized based on morphological, cultural, and VITEK MS methods. Molecular identification using 16S rDNA sequencing and phylogenetic analysis confirmed its identity. Fermentation conditions, including pH, temperature, time, and agitation rate, were figured out to maximize HA production. The basal medium, comprising sucrose (7.0%) as the carbon source and yeast extract + peptone (1.25% each) as nitrogen substrates, favored the highest HA production at pH 8.0, for 30 h, at 30°C, and 180 rpm agitation. The average maximized HA concentration reached 1.5 g L− 1. Furthermore, bacterial HA exhibited a significant inhibitory effect on three cancer cell lines, with the lowest concentration ranging from 0.98–3.91 µg mL− 1. Conclusions K. pneumoniae H15 isolated from animal feces demonstrated promising potential for HA production. The most favorable fermentation conditions led to a high HA yield. The inhibitory effect of bacterial HA on cancer cell lines highlights its potential therapeutic applications. These findings contribute to the understanding and utilization of HA in various industries and therapeutic applications.