If you are running an incorporated business you as an owner would take any investment money you want to put into the company in the Business Owner Contributions (equity investment account)/Business Checking account.
You can easily do this by writing a personal check to your company and writing Owner Contribution by Your Title, First name Middle Initial Last Name on the For line.
Just remember you need to accurately record your personal investments into your business for accounting purposes. Easiest way is writing checks, which the bank will record the front and back of when you deposit them. If there is an emergency and you need to get money to the account faster a transfer would be ok too as long as it is properly recorded in your business accounting ledger.
If your an LLC or S-Corp it may work fine since the taxes would fall through to you. If you are a C-Corp you would want to insure these are kept separate as a C-Corp pays their own taxes which would be separate from your personal income taxes.
To make sure though I would recommend you and the other owners visit a business accountant (hire one that is good and keep them on retainer or have someone that manages your books) so they can give you a better run down and the legal requirements you have to follow and account for.