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Abstract: The limited resources on Earth as well as the energy demand of the ever-increasing population urges us to develop new sustainable processes that cover the use of renewable energy and raw materials. In this context, coupling light with biological systems or enzymes for chemical synthesis is one possible way to achieve sustainable processes as light is a powerful and almost ideal source of energy. In recent years, the field of photobiocatalysis has emerged which brought together two sustainable as well as two research-intensive fields: Photocatalysis and biocatalysis. In this thesis, photo(bio)catalytic transformations were investigated employing light-dependent protochlorophyllide oxidoreductases and an unspecific peroxygenase. In the first part of this study, the library of light-dependent protochlorophyllide oxidoreductases (LPORs) was expanded and the potential of LPORs as biocatalysts was explored. LPORs require light for their natural reaction and catalyze the NADPH-dependent reduction of a C=C in an N-heterocycle of protochlorophyllide, a precursor of chlorophyll. Five LPORs were identified by a sequence search and four of them were well expressible in Escherichia coli and displayed activity. Overall, the study showed that LPORs are easily accessible and possess properties that are required for an efficient biocatalyst. In the second part of this thesis, a light-driven in situ generation of hydrogen peroxide by different carbon nitrides (CNs) was linked to stereoselective hydroxylations catalyzed by an unspecific peroxygenase variant from Agrocybe aegerita (AaeUPO). The chromoselective behavior of the CN allowed to create photo-chemo-enzymatic cascades to form either the (S)- or the (R)-enantiomer of 1-phenylethanol starting from ethylbenzene. The combination of chromoselective photocatalysis with biocatalytic transformation was shown for the first time. The novel concept represents a new tool for controlling reactivity and stereoselectivity in organic synthesis leading to excellent stereoselectivities.