# Fermentation Characteristics and Microbiota during the
## 1 Introduction  
_Myriophyllum aquaticum_ (_M. aquaticum_) is a commonly used aquatic macrophyte for the purification of various water bodies, which has a strong ability to absorb the nutrients, especially nitrogen and phosphorus. Thus, in aquatic environments, _M. aquaticum_ can rapidly grow at the expense of such eutrophic nutrients [1; 2; 3]. In addition, some research has shown that, in effluents with nitrogen concentrations not higher than 20 mg L\({}^{-1}\), _M. aquaticum_ can both absorb nitrogen and phosphorus from sediments through their roots and utilize nutrients from the water through their stems and leaves. Nitrogen and phosphorus are absorbed and used for plant growth, while some organic compounds and heavy metals that are toxic to _M. aquaticum_ may be degraded or immobilized in their bodies [4; 5; 6]. This macrophyte can store a variety of essential nutrients at high concentrations within the tissues, such as proteins with a relatively balanced amino acid composition, various trace elements, and vitamins and essential fatty acids. Therefore, these properties make it an ideal food for farming livestock [4; 5; 6; 7].  
However, the water content of _M. aquaticum_ is usually above 90%, making it susceptible to spoilage during long-term preservation, a problem that needs to be addressed during its conversion into poultry feed. It is well known that silage can be preserved for a long time and is a major component of food for livestock in agriculture and farming livestock. Therefore, making silage from _M. aquaticum_ may be a viable solution to this problem.  
Thus, we hypothesized that the inoculation of lactic acid bacteria (LAB) could promote the fermentation of _M. aquaticum_ into silage and also improve the quality and nutrient composition of silage.  
A large quantity of research has shown that the lactic acid bacteria were the main microbial population that attached to the surface of silage and promoted its fermentation [8; 9; 10]. The addition of lactic acid bacteria inoculants can ensure the sufficient amount of lactic acid bacteria for fermentation in the early stage of ensiling, and enable the silage to enter the lactic acid fermentation stage as soon as possible [11]. _Lactobacillus buchneri_ consumes more nutrients in silage during ensiling. However, _Lactobacillus buchneri_ is more resistant to fungi that can degrade lactic acid, so it can improve the aerobic stability of silage and feed quality. Therefore, the loss of feed nutrients can be compensated by improving the production [12; 13; 14].  
In the present study, _M. aquaticum_ was harvested from a constructed wetland and processed into high-quality silage through reducing the water content for forage purposes. In order to improve the quality of _M. aquaticum_ silage, two lactic acid bacteria (LAB) inoculants, _Lactobacillus buchneri_ (LB) and _Lactobacillus plantarum_ (LP), were fermented with the processed _M. aquaticum_ silage. The aim of this study is to investigate the effects of LP and LB on the fermentation quality and the bacterial and fungal communities in _M. aquaticum_ silage during ensiling. This work was conducted with the perspective of exploring a rational pathway for future applications in animal forage.