Mining bacterial genomes for laccases University of Ljubljana, Biotechnical Faculty Dept. of Food Science and Technology, Chair of Microbiology Mining bacterial genomes for laccases Luka Ausec, Marko Verce, Miha Črnigoj, Vesna Jerman, Ines Mandić-Mulec The 2nd International Symposium “VERA JOHANIDES”, Zagreb, May 11 2013

Why care about laccases What do they do? How do they do it?

Why care about laccases What do they do? How do they do it? Environmentally friendly

Fungal vs. Bacterial Laccases Ease of pruduction Substrate range pH and temperature optimum Salt tolerance

Sources of novel bacterial laccases DNA potential Activty related cultured strains unknown known metagenomics bioinformatics

From genomes to pool of potentials 75% of genes encode signal peptides 2,200 draft and completed genomes 1,240 putative laccase genes 6.5 % on plasmids Ausec, Zakrzewski et al., PLoS ONE 2011

Mining the pool, #1: extremophile Laccase from Thioalkalivibrio sp. substrates substrate optimal pH ABTS 5 K4Fe(CN)6 pyrocatechol 8 pyrogallol 7 2,6-DMP 9.5 syringaldehyde syringic acid N.A. syringaldazine guaiacol Vanillic acid ferulic acid tyrosine pH optima pH

Mining the pool, #2: anaerobe Laccase from Geobacter metallireducens pH optimum temperature optimum

Conclusions Bacterial laccases are diverse Bioinformatic (HMM-based) approaches successful Bacterial laccases have promissing traits for biotechnological applications

Thank you. luka.ausec@bf.uni-lj.si

Bioinformatic analysis of bacterial laccase-like genes >2200 completed and draft bacterial genomes METHODS: profile Hidden Markov Models (pHMM) 5 models constructed

2-domain laccases 3-domain laccases

Figure 3 - List of species encoding laccase genes and possessing plasmids in their genomes. The bars represent the number of laccase genes in the genome (black) and the number of laccase genes on plasmids (gray). The length of the bar shows the total number of genes for each organism. 76 genes on plasmids of 46 organisms