*Article* **Micrococcin P1 and P2 from Epibiotic Bacteria Associated with Isolates of** *Moorea producens* **from Kenya**

**Thomas Dzeha 1,2,\*, Michael John Hall <sup>3</sup> and James Grant Burgess <sup>3</sup>**


**\*** Correspondence: thomas.dzeha@gmail.com

**Abstract:** Epibiotic bacteria associated with the filamentous marine cyanobacterium *Moorea producens* were explored as a novel source of antibiotics and to establish whether they can produce cyclodepsipeptides on their own. Here, we report the isolation of micrococcin P1 (**1**) (C48H49N13O9S6; obs. *m*/*z* 1144.21930/572.60381) and micrococcin P2 (**2**) (C48H47N13O9S6; obs. *m*/*z* 1142.20446/571.60370) from a strain of *Bacillus marisflavi* isolated from *M. producens*' filaments. Interestingly, most bacteria isolated from *M. producens*' filaments were found to be human pathogens. Stalked diatoms on the filaments suggested a possible terrestrial origin of some epibionts. CuSO4·5H2O assisted differential genomic DNA isolation and phylogenetic analysis showed that a Kenyan strain of *M. producens* differed from *L. majuscula* strain CCAP 1446/4 and *L. majuscula* clones. Organic extracts of the epibiotic bacteria *Pseudoalteromonas carrageenovora* and *Ochrobactrum anthropi* did not produce cyclodepsipeptides. Further characterization of 24 Firmicutes strains from *M. producens* identified extracts of *B. marisflavi* as most active. Our results showed that the genetic basis for synthesizing micrococcin P1 (**1**), discovered in *Bacillus cereus* ATCC 14579, is species/strain-dependent and this reinforces the need for molecular identification of *M. producens* species worldwide and their epibionts. These findings indicate that *M. producens*-associated bacteria are an overlooked source of antimicrobial compounds.

**Keywords:** *Moorea producens*; CuSO4·5H2O assisted; differential gDNA isolation; filamentous bacteria; micrococcin P1 and P2; stalked diatoms
