al., 2016; Seuylemezian et al.). The development of a custom database of MALDI-TOF MS profiles of bacterial isolates obtained from spacecraft and associated cleanroom environments has led to the successful identification of 454 bacterial isolates in concurrence with their 16S rRNA gene sequence-based classifications (Seuylemezian et al.). In this study, authors also observed that MALDI-TOF MS could resolve strain-level variations, identified potential novel species and distinguished between members of taxonomic groups, which is not possible using conventional 16S rRNA gene sequencing (Seuylemezian et al.). The results of both 16S rRNA gene sequence-based EzBioCloud Identify service (REF/site) and the MALDI Biotyper database corroborated well in identifying the bacterial strains up to the genus-level, except four unreliably identification by the MALDI Biotyper method (Strejcek et al.). The study also highlighted that only ~35% species-level identifications by MALDI Biotyper could coincide with those identified by 16S rRNA gene sequencing analysis, indicating weak species-level identification by MALDI-TOF MS (Strejcek et al.). Insufficient coverage of bacterial species in the databases has been suggested as the primary reason for these discrepancies (Strejcek et al.). Lack of public repository to submit the new spectral references generated by researchers further worsen this problem (Seuylemezian et al.; Strejcek et al.). The problem worsens in the absence of clear standards and tools to verify the accuracy of the reference profiles. However, the attempts are being made to define a universal MALDI spectral database (Rahi et al., 2016). Simultaneous, efforts have been made to develop user-to-user internet platforms like MALDI-UP specifically designed to facilitate the exchange of in-house MALDI spectral database entries (Rau et al., 2016). In addition to this, researchers might be sharing the spectral database formally and informally, and such exercise will help to develop a consensus on the universal codes for the high-quality spectral entries. All the database repository efforts and online user-to-user platforms have hidden challenges of erroneous database entries, the requirement of continuous curation and validation. These challenges could be the bottleneck to spectral data sharing and repository. The deposition of microbial strains with Microbial Biological Resource Centers (mBRCs) to make them accessible to the research community for verifications and validations of the MALDI-TOF MS spectral database could be a solution to this problem. Although the biodiversity laws of several countries do not allow free movement of microbial cultures, hindering such international efforts (Soltanighias et al., 2018). Blind classification of the microbial strains and inter-lab comparisons could help validate the newly generated spectral profiles. The availability of freely accessible, well-curated MALDI-TOF MS spectra database that allows query search using a web-based interface, comparable to BLAST search on the NCBI GenBank website and databases, could help researchers to identify microbial isolates, without adding spectral profiles into their in-house database (Normand et al., 2017). In a collaborative effort, researchers from five laboratories in France and Belgium developed a free access software to scan a fungal database, which includes spectra of strains belonging to 938 species and 246 genera (Normand et al., 2017). Although at present this tool is limited to the identification of fungi, similar tools can be developed for other microbial groups, and here the mBRCs, need to play a significant proactive role as they have extensive collections of well-curated microbial strains. The quality and accuracy of MALDI-TOF MS spectra can be influenced by the sample preparation methods, matrix components, and type of material analyzed (Lima et al.). During the identification of an extensive collection of microorganisms isolated from cellular phone surfaces, it was observed that quality filtering of MALDI-TOF MS spectrum, improving sample processing methods and enriching the spectral database lead to better and highly reliable results for microbial identifications by MALDI-TOF MS (Kurli et al.). In this study, genus-level identity was achieved for nearly 80% isolates (Kurli et al.). Improvements in the quality of MALDI- TOF MS spectrum (i.e., peak number and intensity) can reduce the number of no reliable identification and also lower the number of erroneous identification (Kurli et al.). If we could find feasible solutions for the challenges associated with MALDI- TOF MS, this technique has the potential to become a 'golden standard' for the identification of diverse groups of bacteria and fungi (Lima et al.). The development of newer algorithms and sample processing methods will improve the applications of MALDI-TOF MS and increase its relevance in microbial ecology studies. Further standardization and ease of accessibility of the mass spectral libraries from variety of environmental sources, and not just clinical origin, will make it the method of choice for microbial ecology studies. Application of the MALDI-TOF MS in large- scale screening and identification studies will increase in the near future, due to the advances in the automation and de-replication, and lead to the discovery of novel microbial species.