## 1 Introduction  
Cyanobacteria are often assumed to be the first oxygenic photosynthetic organisms [1] and have persisted since the Archean Eon [2]. As pivotal primary producers and pioneer species, they exhibit outstanding stress resilience [3]. Scientists have conducted numerous simulations on the response of cyanobacteria to extreme conditions, including polar regions [4], space radiation [5, 6], a high-chlorine salt environment in the surface of Mars [7], Martian-like pure CO\({}_{2}\) atmosphere conditions [8], high temperature [5], and high light [9], in anticipation that it can become a pioneer species to transform outer planets and reserve bioenergy during disasters. Studies have demonstrated that cyanobacteria, especially _Microystis aeruginosa_, survive in extreme environments, although oxidative stress is produced [10, 11]. In addition to their response to extreme conditions, studies on the response of cyanobacteria during storage and transport is essential to determine their potential as pioneer species or reserve bioenergy [12]. A widely known approach to cyanobacterial storage is controlling the temperature and light intensity; cyanobacteria are generally stored in chilled conditions (either on ice or refrigerated) and kept in the dark [13]. It is generally understood that fluctuations in temperature and light intensity can affect metabolic activities in cyanobacteria. For instance,_Pseudanabena_ species exhibit varying chlorophyll-a and 2-MIB (2-Methylisoborneol) production at different temperatures, peaking at 35 \({}^{\circ}\)C and diminishing at 15 \({}^{\circ}\)C [14]. Cyanobacteria such as _M. aeruginosa_ experience oxidative stress under high light conditions [15]. Furthermore, in our previous study [16], _M. aeruginosa_ was exposed to extreme light for eight days, followed by an eight-day recovery under optimal conditions. Changes in response to light exposure and postexposure recovery ability were observed. The results showed that _M. aeruginosa_ could recover rapidly from high light intensity stress within the period [16]. Conversely, some studies indicate that a short period of darkness, up to 30 days, harms the growth of cyanobacteria; dramatic changes occur in the growth rate, organic secretion, redox state, and pH of cyanobacterial cells [17; 18; 19]. Numerous studies have explored the variation of cyanobacteria in different storage conditions, such as low temperatures and light exclusion [20; 21; 22]. However, less attention has been paid to cyanobacterial recovery after prolonged periods of darkness, especially due to storage, transportation, or even during space transport for colonization [20]. A recent study has shown that proper cold storage induces vernalization and accelerates the recovery of _M. aeruginosa_. Samples stored at 4 \({}^{\circ}\)C and 10 \({}^{\circ}\)C exhibited a significantly enhanced growth rate compared to those at 28 \({}^{\circ}\)C [21]. Some researchers have suggested that the recovery of cyanobacteria is affected by combined conditions of long-term low temperature and dark storage. After one month of low-temperature dark culture, the growth rate of _M. aeruginosa_ was only approximately 87.1% of its original rate [22]. However, there have been no studies on cyanobacterial response and recovery after prolonged darkness. Maintaining a cold chain transport at 4 \({}^{\circ}\)C is both challenging and costly in remote areas requiring ecological modification. Moreover, organisms intended for bioenergy reserves should not require extra energy for temperature preservation. Therefore, studying cyanobacterial growth and storage capacity at ambient temperature is imperative. In this study, unlike prior research, our experiment focused on dark storage without the need for cold conditions, extending the darkness duration to one year (360 days) and focusing on the recovery ability of cyanobacteria after prolonged dark treatment periods. This study addresses a research gap regarding the recovery of cyanobacteria after long dark exposure without cold conservation.