# Characterization of Two Hydrogen Peroxide Resistant Peroxidases from _Rhodococcus apacus_ 1 Cp  
[PERSON]  
1 Microbial Biotechnology, Ruhr University Bochum, Universitatsstrastra 150, 44780 Bochum, Germany; [PERSON]DDRESS] (A.C.R.N.); [PERSON] (A.G.B.)
2 Institute of Biosciences, Environmental Microbiology, TU Bergakademie Freiberg, Leipzigter Str. 29, 09599 Freiberg, Germany; [EMAIL_ADDRESS]
3 Allgemeine Bochemie, Technische Universitat Dresden, 01062 Dresden, Germany; [PERSON]ESS] (A.M.); [PERSON]K.-H.v.P.)
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increase its stability towards its substrate since it is generally considered that the presence of sensitive amino acids close to the heme group is responsible for the peroxide inactivation. In the DypB of _Rhodococcus jostii_, mutations to the Asp153 have been shown to have a beneficial effect in this parameter [20]. Another example was the introduction of the T134V and M212L mutations in the _Pp_Dyp from _Pseudomonas putida_[21].  
Meanwhile, the difficulty of heterologous expression posed a challenge earlier since the first DyPs characterized were found in fungi. They tend to present high levels of glycosylation making it difficult to express in organisms like _Escherichia coli_. This issue was overcome after the discovery and subsequent heterologous expression of bacterial DyPs. To date, several bacterial DyPs have been described in many different organisms such as cyanobacteria [22], bacillus [23], actinomycetes such as _Thermobifida fusca_[24; 25; 26], _Amyclatopsis_[27], _Rhodococcus jostii_[28; 29; 30], _Saccharomyces viridis_[31] and Gammaproteabacteria such as different species of _Pseudomonas_[32; 33; 34] or _E. coli_[35]. Strategies to improve protein production in _E. coli_ such as the addition of hemin still needs to be explored on since it does not incorporate heme properly. Despite the growing data on these bacterial peroxididases, optimizing protein production is still needed to be explored on.  
Actinobacteria is a phylum well-known for their capacity to degrade organic pollutants. Several research studies have already shown the applicability of actinobacteria such as _Corynebacterium_ sp. [36], _Streptomyces_ sp. [37], and _Rhodococcus_ sp. [38] to name a few. _Rhodococcus_ sp. has been a subject of interest in different biotechnological applications due to the promising enzymes it harbors. _Rhodococcus opacus_ has been a subject of biotechnological interest for its capacity to produce fatty acids [39; 40]. Moreover, it is capable of utilizing several different carbon sources as well as its stability towards different organic solvents makes it an extremely interesting option for industrial applications [41; 42]. Many interesting xenobiotic-degrading enzymes have already been characterized such as styrene monooxygenases [43], styrene oxide isomerases [44], phenol hydroxylases [45], azobenzene reductases [46], and among others. Despite the myriad of enzymes found and studied on _R. opacus_ 1 CP, the dye decolorizing peroxididases, DypA and DypB, are not established yet.  
Therefore, the study aimed to clone, express, purify, and characterize the biochemical properties of DypA and DypB. Their tolerance towards H2O2 and their potential to degrade dyes of different structures was also investigated. In addition, deeper insights into its mechanism towards Reactive Blue 5 were done.