Dobbs was arrested Nov. 30 — his 25th birthday — for suspicion of driving under the influence and possession of marijuana,Fjallraven Kanken Australia Sale.
Dobbs participated in practice Wednesday. The suspension was announced just after coach Jim Harbaugh addressed the media for the day.
"The San Francisco 49ers organization supports the NFL's code of conduct policy and their recent decision regarding Demarcus,China NFL Jerseys," general manager Trent Baalke said in a statement.
The 49ers, in announcing the penalty jointly with the NFL, said Dobbs would be eligible to return to the active roster on Sept. 9, a day after the reigning NFC champion Niners' season opener at home against the Packers. He can still practice with the team, attend meetings and other activities.
Dobbs' position coach, Jim Tomsula,Steelers Jersey Cheap, said he had spoken with Dobbs.
The third-year pro out of Georgia, who signed as an undrafted free agent in July 2011, had three tackles in 12 games last year. He played primarily on special teams.
"It stems from stuff that happened last year and the incident and everything that happened. The league decided to take action on it and they felt this punishment was fit and I agree with it," Dobbs said after practice Wednesday night. "I've got to deal with my consequences, can't complain about it or do much about it now."
"I've just got to go out and prove what I can do during training camp and preseason, and it means a lot now that I'm not going to be playing the first game," he said. "I've just got to go out there and show my teammates why I deserve to be here and show the people upstairs that kept me why I deserve to be here."
SANTA CLARA, Calif. (AP) — San Francisco 49ers defensive lineman Demarcus Dobbs said he agrees with the NFL's decision to suspend him for one game without pay for a violation of the NFL's substance abuse policy that happened last season.

Dobbs ended last season on injured reserve with a right knee problem, missing the final three regular-season games after getting hurt against Miami on Dec. 9.
He must sit out the team's Week 1 game against Green Bay. Dobbs said he has known for about a month he might still face the suspension.
"My whole thing when it comes to that,Cheap Shoes From China, No. 1, and obviously Demarcus and I have talked and it's unfortunate,Wholesale MLB Jerseys," Tomsula said. "The guy made a mistake, so once you make a mistake you stand up,Air Force One Scontate, you own it, and that's what he's done. I'm not by any means saying what happened was right, but the way he's handled it since he made a mistake has been straight up. I feel really good about that."
"I learned a lot from that situation and I have no intention of repeating it," Dobbs said. "It's unfortunate with the Dallas thing and everything. I feel like I have a second chance to go on with this life I have and this career."
Just more than a week after his own incident, Dallas Cowboys linebacker Jerry Brown died in a Dec. 8 accident in which defensive lineman teammate Josh Brent was the driver. Brent is charged with intoxication manslaughter.
The California Highway Patrol said that Dobbs was involved in a single-car accident in which he hit a chain-link fence and a bush but didn't sustain any injuries. Dobbs later expressed how sorry he was, and lucky, too.
Dobbs is focused on making the team, and thanked Baalke and the organization for keeping him around.