## 1 Introduction  
Microalgal biodiversity remains largely unexplored and bioprospection efforts may represent an opportunity to discover novel metabolites and promote biomass production at lower costs [1,2]. These microorganisms have been widely recognized as a cornerstone for bioeconomy and biorefinery development, due to their high applicability as feedstocks for food, feed, bioplastics, biofertilizers, and biofuels as well as for wastewater treatment and CO\({}_{2}\) mitigation [3, 4, 5]. In Europe, macro- and microalgae were recognized in the Strategic Energy Technological Plan (SET-PLAN) as a part of the key-value chain for advanced biomaterials production. Portugal, as a coastal country, has excellent climatic conditions and a great potential for a sustainable industrial microalgal cultivation [5]. Nevertheless, the high cost of microalgal production is still the main restriction associated with the commercialization of biomass for different commodities [5,6].  
The world's increasing population and the predictions of an insufficient protein supply have led to research on new alternative and unconventional protein sources [7]. Algal biomass is currently considered as a good candidate for this purpose since these photosynthetic aquatic microorganisms are able to synthesize all the essential amino acids and their cultivation does not compete for arable land, as they can be grown in bioreactors [3,5]. Proteins are the main constituents of microalgae and one of the most important products of microalgae-based biorefineries [8]. Interestingly, these proteins, and peptides thereof, are very interesting for functional food applications due to their biological activities, in particular those related to the prevention and reduction of hypertension, oxidative stress, cancer, diabetes, inflammation, and immune disorders [9]. Moreover, as microalgae contain large amounts of pigments (e.g., carotenoids), many of them with known antioxidant properties and biomectically relevant bioactivities, microalgal biomass can be used to fortify or supplement food, feed, and cosmetics, improving their basic market value while providing increased health benefits [10]. This is in line with the expected increase in the worldwide market size of natural pigments fueled by a growing demand for such products by the consumers [3,5].  
Bioprospecting for novel microalgal species and promoting industrial biomass production is key to improving the current portfolio of available strains for different biotechnological applications. The screening for molecules and activities of biotechnological interest as well as the understanding of microalgal ecosystem functioning are essential to develop sustainable and economical solutions for today's civilization and environmental needs [11, 12, 13].  
The present work aimed to characterize and evaluate the biotechnological potential of a new isolate obtained from a pond at the Allmicroalgae facilities whose 18S ribosomal deoxyribonucleic acid (rDNA) sequence is identical to that of _Oophila ambly stomatis_. Interestingly, this sequence clusters together with those of the Stephanosphaerinia macrolade belonging to the genus _Chlorococccum_, suggesting that _O. ambly stomatis_ should be reclassified as _Chlorococccum ambly stomatis_. As the biotechnological use of this novel isolate was the focus of the present work, its growth performance in the pilot and industrial-scale systems was assessed. In addition, its composition in terms of protein, lipids, carbohydrates, and pigments were evaluated to determine the nutritional potential of this microalga.