## 1 Introduction  
Due to the occurrence of fungal resistance to synthetic fungicides, the use of chemical compounds is strictly controlled and their application is subjected to tighter regulations [1; 2]. Therefore, the use of biological substances with antimicrobial properties redirected researchers for the development of novel and stable approaches that are less inducible to antimicrobial resistance in order to replace chemical fungicides, bactericides and pesticides for food preservation and safety as well as plant crop protection. Furthermore, the growing interest in biological food additives has challenged the scientific community to innovate in alternative food preservation and plant crop protection systems. Thus,natural preservatives from sources like bacteria, plants and algae were reported to ensure food safety due to their antimicrobial activity against a wide spectrum of foodborne pathogens [3; 4]. In this regard, dietary antioxidants (i.e., phenolic compounds) have recently attracted extensive attention because of their ubiquity in nature and their various beneficial effects, including antimicrobial, antioxidant, antiinflammatory and antiproliferative activities [5].  
One of the readily available sources of such compounds is by-products from the agro-food industry. For example, pomeranate processing generates a large amount of solid wastes. In fact, per 1000 g of raw pomerangrate fruit, the edible portion accounts for only half (-400 g of juice and 100 g of seeds) and the rest, almost 500 g (e.g., peels), is discarded as waste [6]. Pomeranate peel has remarkable antioxidant and antimicrobial properties. Rich in flavonoids, phenolic acids and tannins, pomeranate peels are known to possess important and diverse biological and pharmacological properties [7; 8]. [PERSON] et al. reported that pomeranate peel exhibits high levels of free radical scavenging activities and strong antimicrobial activity due to its phenolic content [9]. Several studies reported the efficacy of extracts from pomerangate peel to inhibit both Gram-positive and Gram-negative bacterial growth such as foodborne pathogens, spoilage bacteria and human pathogens [10]. It was reported as well that pomeranate extracts display antifungal properties [11]. In fact, some extracts have anti _Candida_ sp. and anti _Saccharomyces cerevisiae_ activities [12] and, more recently, both peel powder and extracts were demonstrated to inhibit the growth of _Penicillium_ spp., two mycotoxicin Aspergillus (_A. flavus_ and _A. ochraceus_) [13], two _Colletotrichum_ strains as well as _Rhizopus stolonifer_, _Botrytis cinerea_, and _Rhizoctonia solani_ strains [14; 15]. Some studies reported that the proportion of carbohydrate in pomeranate peel was about 15% and that the polysaccharides extracted from pomeranate had obvious biological functions [16].  
_Spirulina (Arthospira platensis)_, a microscopic and filamentous cyanobacterium, has been recently recommended as a sustainable, highly nutritional and coofriendly microalgae [17]. _Spirulina_ contains potent antioxidants, free-radical scavengers [18] and is able to inhibit the growth of some Gram-negative, Gram-positive bacteria and yeast such as _Candida albicans_[18]. Polysaccharides extracted from _Spirulina_ have antitumor, antioxidant, antiaging, and antivirus properties [19]. Nevertheless, little information about antifungal properties, especially against mycotoxicin and phytopathogenic fungi, of _Spirulina platensis_ is available in the literature and its potential toxic effects have not been largely investigated.  
To date, there is no study that has addressed mycotoxicin and phytopathogenic properties when pomerangate and _Spirulina_ were combined. Therefore, the objective of this research was to evaluate the composition of _Spirulina_ alone and in combination with pomeranate peel extracts and to study their potential on the antifungal activity. Associations between phytochemical content and antifungal properties were discussed based on Pearson coefficients.