*2.1. In Silico Analysis of Chitin Degrading Machinery and Bioactive Potential in P. rubra S4059*

The genome of S4059 consists of two circular chromosomes, of 4,595,233 bp and 1,348,119 bp, with an average G + C content of 47.71% and 46.93%. Fourteen putative chitinolytic enzymes were identified according to the prediction of the S4059 proteome in Uniprot (proteome ID UP000305729), including seven of the GH18 chitinase family, two of the GH19 chitinase family, and three of the GH20 hexosaminidase family, as well as two lytic polysaccharide monooxygenases (LPMOs) of the auxiliary activity (AA) family 10 (Table 1). All the chitinolytic enzymes contained a signal peptide at the N-terminal, except for one GH19 chitinase (A0A5S3UPT5).

**Table 1.** The chitinolytic machinery in *Pseudoalteromonas rubra* S4059 according to the prediction of the proteome from Uniprot (Proteome ID UP000305729). The signal peptide was predicted using amino acid sequence by SignalIP-5.0 (http://www.cbs.dtu.dk/services/SignalP/ (accessed on 22 September 2018)).


The genome of S4059 harbors nineteen predicted BGCs identified by antiSMASH 6.0, distributed with thirteen on chr I and six on chr II. BGC 2-5, 17, and 18 are non-ribosomal peptide synthetase clusters (NRPs), BGC 8, 13, and 16 are other unspecified ribosomally synthesized and post-translationally modified peptide products (RiPP) clusters, BGC 10, 11, and 15 are the hybrids of NRPs and Type I polyketide (PKs), BGC 7 is a hserlactone BGC, BGC 9 is prodigiosin BGC, and BGC 12, 13 belong to lanthipepride-class. Four of the BGCs located on chr I were predicted to produce indigoidine, kalimantacin A, amonabactin P 750, and prodigiosins (Table S1), however, only the prodigiosin gene cluster was predicted to be conserved to the known BGC with a similarity score of 70%, while the others were below 40% as shown in Table S1. The products of the rest of the BGCs are not known.
