Microcystins, a group of cyclic-heptapeptide hepatoxins, are among the most potent varieties of cyanotoxins. Their presence in aquatic systems has become a major threat to environmental and ecological stability, as well as to public health. Since the first investigation of microcystinase and the corresponding mlr gene cluster in 1996, the genetic approach to microcystins degradation has become a prevalent focus. This study retrieved and evaluated 91 articles from Scopus (1994 – May. 2022) on the decomposition of microcystins specifically with mlr genes, through bibliometrics and content analysis to illustrate leading contributors and up-to-date research hotspots of this subtopic with urgent demand. Furthermore, notable outcomes and a future outlook was summarized as reference for researchers. Results indicated that utilizations of mlr genes and host bacteria are novel advances, as the average year of appearance of key words ‘mlr gene’ ‘genetics’ ‘bacterial protein’ were approximately 2017. China was the most productive with 43 publications, followed by the United States, Japan and Australia with 11 documents each. Journals Chemosphere and Toxins were key publishers with 9 articles each. Three topics: separation from natural strains, determination of degradation pathway and proposal of implementations, were the current keynotes of mlr genes research. Heterologous expression has clarified respective metabolic roles of MlrABCD. Recently, there has been increasing interest in linearized-microcystins: the use of MlrA, the most effective enzyme for microcystins detoxification, is commonly followed by physical or chemical methods to treat the less toxic by-product. Such interdisciplinary approaches, as well as the optimization of mlr expression in recombinant bacteria for bioaugmentation, have been found promising and should be given more recognition in future studies. This work outlines the current research status of using mlr genes for biodegradation, provides insight on potential improvement opportunities, and suggests a future direction towards mlrA-based composite bioremediation.